Document the rig bindings on the tone_changes wire message

CHANGELOG entry for the core rig reader, plus the WS protocol table in
CLAUDE.md, which described `tone_changes` as carrying only base + name.

While in that row: its time key was documented as `time`, but every
producer emits `t` — both the sloppak builder and the legacy XML path.
The 3D highway already carries a comment warning readers about exactly
this discrepancy. Corrected here rather than left sitting next to the
newly-added keys, where a reader would reasonably assume both were
equally reliable.

Signed-off-by: gionnibgud <gionnibgud@gmail.com>

CHANGELOG.md

@@ -8,6 +8,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- **Core reader for source rigs (feedpak 1.18.0).** A pack can declare what a
+  MIDI part should sound like by binding a rig; core now reads that binding and
+  hands it to the client instead of dropping it. Three parts: the
+  `tone_changes` WS message carries the pack's rig bindings (`base_rig`, and
+  `rig` per change) alongside the tone names it already sent; the manifest
+  `rigs:` key loads the pack's rig library (`rigs.json`, spec §7.9) verbatim;
+  and the binding precedence is resolved per spec §5.1/§5.2 — a manifest
+  arrangement entry's `tones` replaces the arrangement JSON's **wholesale**
+  (no field-level merge), while top-level `drum_tones` binds the primary drum
+  part as the fallback a `type: drums` entry's own `tones` outranks. Core
+  deliberately stops there: it does not select a realization or apply the
+  `intent.gm` floor, which belong to whatever actually voices the part. Packs
+  that bind no rig produce a byte-identical `tone_changes` payload, so existing
+  consumers are unaffected.
 - **Opt-in career venue packs (#122)** — higher-tier venue crowd media
   (`club`, `arena`) is no longer bundled; the app downloads each pack on demand
   from its release when you reach the venue (sha256-verified), keeping the

CLAUDE.md

@@ -690,7 +690,7 @@ The highway WebSocket at `/ws/highway/{filename}?arrangement={index}` streams th
 | `anchors` | `{ type, data: [{ time, fret, width }] }` | Fret zoom anchors |
 | `chord_templates` | `{ type, data: [{ name, frets: [6] }] }` | Named chord shapes |
 | `lyrics` | `{ type, data: [{ w, t, d }], source }` | Syllables: `w`=word, `t`=time, `d`=duration. `-` joins to previous, `+` = line break. `source` is one of `"xml"`, `"whisperx"`, `"user"` — UI can use it to render an "auto-transcribed" badge for `whisperx`. Sloppaks always include `source` (legacy sloppaks without a `lyrics_source` manifest key default to `"xml"` at load time). Loose folders set it based on which extractor matched. Absent only when no lyrics fired the message at all |
-| `tone_changes` | `{ type: 'tone_changes', base, data: [{ time, name }] }` | Optional — tone change events relative to the arrangement base tone; only sent if tones were found |
+| `tone_changes` | `{ type: 'tone_changes', base, base_rig?, data: [{ t, name, rig? }] }` | Optional — tone change events relative to the arrangement base tone; only sent if tones were found. Note the time key is **`t`**, not `time` (both the sloppak path and the legacy XML path emit `t`). `base_rig` and each entry's `rig` are the pack's **rig bindings** — ids into [`rigs.json`](https://github.com/got-feedback/feedpak-spec/blob/main/spec/feedpak-v1.md#79-rigsjson) (feedpak §6.9/§7.9), carried through verbatim and **not** resolved by core: selecting a realization and applying the `intent.gm` floor belong to whatever voices the part. Both are **omitted entirely** when the chart binds no rig, so consumers predating the rig model see the payload they always did. |
 | `notes` | `{ type, data: [{ t, s, f, sus, ho, po, sl, bn, ... }] }` | Single notes |
 | `chords` | `{ type, data: [{ t, notes: [{ s, f, sus, ... }] }] }` | Chord events |
 | `phrases` | `{ type, data: [{ start_time, end_time, max_difficulty, levels: [{ difficulty, notes, chords, anchors, handshapes }] }], total }` | Optional — per-phrase difficulty ladder for master-difficulty slider (feedBack#48). Only sent when the source chart carries multi-level phrase data (phrase-aware sloppak). Sent in chunks (`data` is a batch, `total` is the full count across messages) to avoid multi-MB single frames. Absent for GP imports and legacy sloppak; consumers must treat missing message as "single fixed difficulty — slider disabled". |

lib/midi_import.py

@@ -1,6 +1,6 @@
 """MIDI file import — list tracks and convert tracks to sloppak payloads.
 
-Three parallel flows live here:
+Two parallel flows live here:
 
 - **Keys path** (`list_midi_tracks` + `convert_midi_track_to_keys_wire`):
   filters channel-9 out and emits a standard guitar-style arrangement that
@@ -11,19 +11,12 @@ Three parallel flows live here:
   `docs/sloppak-spec.md` §5.3, ready to drop alongside the sloppak
   manifest's `drum_tab:` key.
 
-- **Lyrics path** (`extract_midi_lyrics`): reads SMF Lyric (0x05) meta events
-  (with a Text-event fallback on vocal-ish tracks, covering karaoke `.kar`
-  files) and emits the `lyrics.json` / `vocal_pitch.json` sidecar payloads
-  documented in feedpak-spec §7.1 / §7.2, ready to drop alongside the
-  manifest's `lyrics:` / `lyrics_source:` / `vocal_pitch:` keys.
-
-The editor's track picker uses the first two for the +Drums and +Keys modals.
+The editor's track picker uses both for the +Drums and +Keys modals.
 """
 
 from __future__ import annotations
 
 import math
-import re
 from bisect import bisect_right
 from collections import deque
 from typing import Callable
@@ -784,430 +777,3 @@ def convert_drum_track_from_midi(
         ],
         "hits": out_hits,
     }
-
-
-# ── Lyrics + vocal-melody extraction ─────────────────────────────────────────
-
-# Vocal-track detection, mirroring the idiom in `lib/gp2rs_gpx.py`'s
-# `_is_vocal_track` (GM voice/choir/lead-voice programs + name keywords).
-# Kept as a local copy because that helper consumes gp2rs_gpx's own GP track
-# dicts, not raw MIDI tracks. "melody" is added to the name hints: karaoke
-# MIDIs commonly label the sung line "Melody" rather than "Vocals".
-_VOCAL_MIDI_PROGRAMS = {52, 53, 54, 85, 86, 87}  # Choir Aahs, Voice Oohs, Synth Voice, Lead 5-7 (voice)
-_VOCAL_NAME_HINTS = ("vocal", "voice", "vox", "sing", "lyric", "choir", "melody")
-
-# A dedicated karaoke *text* track (SMF 0x01 Text events, `.kar` convention)
-# is usually noteless and named "Words" or "Soft Karaoke" — names the vocal
-# hints above don't catch. Only the Text-event fallback consults this wider
-# set; note-track detection sticks to the gp2rs_gpx idiom.
-_LYRIC_TEXT_TRACK_HINTS = _VOCAL_NAME_HINTS + ("words", "karaoke")
-
-# A lyric event pairs with a vocal note-on when their onsets sit within this
-# window. Karaoke files place the lyric event at (or a hair before) the
-# note-on tick, so real matches are ~0; the window only absorbs sloppy
-# authoring, and staying well under a typical syllable gap keeps a melisma's
-# extra notes from being stolen by the next syllable.
-_LYRIC_PAIR_TOLERANCE_S = 0.30
-
-# Duration bounds for lyric entries with no pairable note (spoken lines,
-# lyrics-only files). "Until the next lyric event" is the natural display
-# duration, capped so a verse-final syllable before a long instrumental
-# break doesn't linger on screen, and floored so simultaneous/out-of-order
-# events can't produce a zero or negative duration.
-_UNPAIRED_LYRIC_MAX_D = 2.0
-_UNPAIRED_LYRIC_MIN_D = 0.1
-
-# Leading/word/trailing whitespace splitter for lyric tokens. DOTALL so
-# embedded newlines land in a group rather than killing the match.
-_LYRIC_TOKEN_RE = re.compile(r"^(\s*)(.*?)(\s*)$", re.S)
-
-
-def _scan_tracks_for_lyrics(midi: mido.MidiFile) -> list[dict]:
-    """One pass per track collecting the raw material `extract_midi_lyrics`
-    needs: name, per-channel programs, melodic (non-drum) notes with their
-    on/off ticks, and Lyric/Text meta events.
-
-    Each item: {name, channel_programs: {ch: program}, notes:
-    [(start_tick, end_tick, pitch, channel)], lyric_events: [(tick, text)],
-    text_events: [(tick, text)]}. Note pairing uses the same FIFO
-    note_on/note_off matching as the keys converter so retriggers don't
-    cross-wire durations.
-    """
-    out: list[dict] = []
-    for track in midi.tracks:
-        name = ""
-        channel_programs: dict[int, int] = {}
-        lyric_events: list[tuple[int, str]] = []
-        text_events: list[tuple[int, str]] = []
-        notes: list[tuple[int, int, int, int]] = []
-        active: dict[tuple[int, int], deque[int]] = {}
-        abs_tick = 0
-        for msg in track:
-            abs_tick += msg.time
-            if msg.type == "track_name" and not name:
-                name = msg.name or ""
-            elif msg.type == "lyrics":
-                lyric_events.append((abs_tick, msg.text or ""))
-            elif msg.type == "text":
-                text_events.append((abs_tick, msg.text or ""))
-            elif msg.type == "program_change":
-                ch = int(getattr(msg, "channel", -1))
-                if ch != 9 and ch not in channel_programs:
-                    channel_programs[ch] = int(msg.program)
-            elif msg.type == "note_on" and int(getattr(msg, "velocity", 0)) > 0:
-                ch = int(getattr(msg, "channel", -1))
-                if ch == 9:
-                    continue
-                active.setdefault((ch, int(msg.note)), deque()).append(abs_tick)
-            elif msg.type == "note_off" or (
-                msg.type == "note_on" and int(getattr(msg, "velocity", 0)) == 0
-            ):
-                ch = int(getattr(msg, "channel", -1))
-                pitch = int(msg.note)
-                stack = active.get((ch, pitch))
-                if not stack:
-                    continue
-                start_tick = stack.popleft()
-                if not stack:
-                    active.pop((ch, pitch), None)
-                notes.append((start_tick, abs_tick, pitch, ch))
-        # Close anything left hanging at end-of-track, mirroring the keys
-        # converter's end-of-track sweep.
-        for (ch, pitch), starts in active.items():
-            for start_tick in starts:
-                notes.append((start_tick, abs_tick, pitch, ch))
-        notes.sort(key=lambda n: n[0])
-        out.append({
-            "name": name,
-            "channel_programs": channel_programs,
-            "notes": notes,
-            "lyric_events": lyric_events,
-            "text_events": text_events,
-        })
-    return out
-
-
-def _name_matches(name: str, hints: tuple[str, ...]) -> bool:
-    name_l = (name or "").lower()
-    return any(h in name_l for h in hints)
-
-
-def _normalize_lyric_tokens(events: list[tuple[int, str]]) -> list[dict]:
-    """Turn raw lyric/text meta events into clean syllable tokens.
-
-    Handles both encodings seen in the wild:
-
-    - **`.kar` / karaoke convention**: `/` prefix = new line, `\\` prefix =
-      new paragraph (both mean "the previous syllable ended a line"),
-      `-` suffix = syllable joins the next one, `@`-prefixed tokens are
-      file metadata (`@KMIDI`, `@T<title>`, ...) and are dropped.
-    - **Plain Lyric-event convention**: word boundaries carried by leading
-      or trailing spaces; line breaks carried by embedded CR/LF.
-
-    Each token: {tick, word, lead_ws, trail_ws, line_end}. Spacing-only and
-    newline-only events don't emit a token — they fold their meaning
-    (word-break / line-end) onto the previous one.
-    """
-    toks: list[dict] = []
-    for tick, raw in events:
-        text = "" if raw is None else str(raw)
-        if not text:
-            continue
-        if text.lstrip().startswith(("@", "%")):
-            # .kar metadata / sequencer directives, not sung text.
-            continue
-        kar_break = text[0] in ("/", "\\")
-        if kar_break:
-            text = text[1:]
-        m = _LYRIC_TOKEN_RE.match(text)
-        head, body, tail = m.group(1), m.group(2), m.group(3)
-        nl_before = ("\n" in head) or ("\r" in head)
-        nl_after = ("\n" in tail) or ("\r" in tail)
-        if "\n" in body or "\r" in body:
-            # Rare multi-line event: keep it one token, treat the break as
-            # trailing so the line ends after this token.
-            body = re.sub(r"[\r\n]+", " ", body).strip()
-            nl_after = True
-        if (kar_break or nl_before) and toks:
-            toks[-1]["line_end"] = True
-        if not body:
-            # Pure spacing/newline token: fold onto the previous syllable.
-            if nl_after and toks:
-                toks[-1]["line_end"] = True
-            if toks:
-                toks[-1]["trail_ws"] = True
-            continue
-        toks.append({
-            "tick": tick,
-            "word": body,
-            "lead_ws": bool(head),
-            "trail_ws": bool(tail),
-            "line_end": nl_after,
-        })
-    return toks
-
-
-def _apply_word_conventions(toks: list[dict]) -> list[str]:
-    """Map tokens to spec §7.1 `w` strings: trailing ``-`` joins to the next
-    syllable, trailing ``+`` ends a line.
-
-    Which join convention the source used is detected per stream:
-
-    - Any token already carrying a ``-`` suffix → the stream is
-      hyphen-delimited (`.kar` style); those suffixes are the spec's own
-      join marker and pass through untouched.
-    - Otherwise, if the stream carries any spacing at all → space-delimited:
-      a token with no trailing space followed by a token with no leading
-      space is a mid-word syllable and gains a ``-``.
-    - No hyphens and no spacing anywhere → the tokens are whole words
-      (common for Text-event lyrics); no joins are synthesized.
-    """
-    has_hyphens = any(t["word"].endswith("-") for t in toks)
-    has_spacing = any(t["lead_ws"] or t["trail_ws"] for t in toks)
-    words: list[str] = []
-    for i, tk in enumerate(toks):
-        w = tk["word"]
-        nxt = toks[i + 1] if i + 1 < len(toks) else None
-        if tk["line_end"]:
-            # A join can't cross a line break — the line marker wins.
-            if w.endswith("-"):
-                w = w[:-1]
-            if w and not w.endswith("+"):
-                w += "+"
-        elif nxt is not None and not has_hyphens and has_spacing:
-            if not tk["trail_ws"] and not nxt["lead_ws"] and not w.endswith("-"):
-                w += "-"
-        words.append(w)
-    return words
-
-
-def _select_vocal_notes(
-    scans: list[dict],
-    lyric_track_index: int,
-    midi_type: int,
-) -> tuple[int, list[tuple[int, int, int, int]]] | None:
-    """Pick the note pool the lyric syllables should be pitch-paired with.
-
-    Returns ``(track_index, notes)`` or ``None`` when no vocal melody is
-    identifiable (→ lyrics-only import). Selection order:
-
-    1. The lyric-carrying track itself, when it has notes:
-       - channels with a vocal GM program → only those channels' notes
-         (isolates the sung line inside a format-0 everything-in-one-track
-         file);
-       - vocal-ish track name → all its non-drum notes;
-       - SMF type 1/2 with neither → still trusted: a track that interleaves
-         per-syllable Lyric events with its own notes *is* the karaoke
-         melody by construction. Format-0 files don't get this benefit of
-         the doubt — there the single track holds every instrument, so
-         without a vocal program/name there is no way to isolate the melody
-         and we fall back to lyrics-only.
-    2. Otherwise (dedicated noteless "Words" track), the vocal-ish track —
-       by name hint or vocal GM program, mirroring gp2rs_gpx — with the
-       most notes; within it, vocal-program channels only when present.
-    """
-    def _vocal_channels(scan: dict) -> set[int]:
-        return {
-            ch for ch, prog in scan["channel_programs"].items()
-            if prog in _VOCAL_MIDI_PROGRAMS
-        }
-
-    def _pool(scan: dict) -> list[tuple[int, int, int, int]]:
-        chans = _vocal_channels(scan)
-        if chans:
-            return [n for n in scan["notes"] if n[3] in chans]
-        return scan["notes"]
-
-    src = scans[lyric_track_index]
-    if src["notes"]:
-        if _vocal_channels(src) or _name_matches(src["name"], _VOCAL_NAME_HINTS):
-            return lyric_track_index, _pool(src)
-        if midi_type != 0:
-            return lyric_track_index, src["notes"]
-        return None
-
-    best: tuple[int, list] | None = None
-    for i, scan in enumerate(scans):
-        if not scan["notes"]:
-            continue
-        if not (_vocal_channels(scan)
-                or _name_matches(scan["name"], _VOCAL_NAME_HINTS)):
-            continue
-        pool = _pool(scan)
-        if pool and (best is None or len(pool) > len(best[1])):
-            best = (i, pool)
-    return best
-
-
-def extract_midi_lyrics(midi_path: str, audio_offset: float = 0.0) -> dict | None:
-    """Extract lyrics (and, when pairable, the vocal melody) from a `.mid`.
-
-    Returns ``None`` when the file carries no usable lyric events — callers
-    then change nothing, leaving any existing manifest keys and sidecar
-    files untouched. Otherwise returns::
-
-        {
-            "lyrics": [{"t": float, "d": float, "w": str}, ...],
-            "lyrics_source": "authored",
-            "vocal_pitch": {"version": 1,
-                            "notes": [{"t", "d", "midi"}, ...]} | None,
-        }
-
-    ``lyrics`` is the feedpak `lyrics.json` payload (spec §7.1: flat list,
-    no version field; ``w`` uses trailing ``-`` for syllable joins and
-    trailing ``+`` for line ends). ``vocal_pitch`` is the `vocal_pitch.json`
-    payload (spec §7.2, same shape as gp2rs_gpx's
-    ``convert_vocal_track_to_pitch_sidecar`` and the lyrics-karaoke
-    plugin's ``_persist_pitch``) — ``None`` when no vocal note track could
-    be identified, in which case the caller writes `lyrics.json` only.
-    ``lyrics_source`` is always ``"authored"`` (spec §7.1 vocabulary):
-    lyric meta events are chart-author data, not machine transcription.
-
-    Callers assembling a pack write ``lyrics.json`` /
-    ``vocal_pitch.json`` and set the manifest ``lyrics`` /
-    ``lyrics_source`` / ``vocal_pitch`` keys — and should do so only for
-    keys not already present, so an import never clobbers lyrics that
-    arrived from another source.
-
-    Sourcing rules:
-
-    - Lyric text comes from SMF Lyric (0x05) meta events — the track with
-      the most of them wins when several carry some. When the file has
-      none at all, Text (0x01) events are accepted as a fallback, but only
-      from a vocal-ish track (gp2rs_gpx-style name/program detection,
-      widened with "words"/"karaoke" for `.kar` text tracks) — Text events
-      elsewhere are copyright notices / markers, not lyrics.
-    - `.kar` conventions are normalized (see ``_normalize_lyric_tokens`` /
-      ``_apply_word_conventions``): ``/`` and ``\\`` line-break prefixes
-      become the spec's ``+`` suffix on the previous syllable, ``@``
-      metadata tokens are dropped, ``-`` hyphen joins pass through.
-    - Each syllable is paired with the vocal note (see
-      ``_select_vocal_notes``) whose onset falls within
-      ``_LYRIC_PAIR_TOLERANCE_S`` of the lyric event, greedily in time
-      order, one note per syllable. Paired syllables snap ``t``/``d`` to
-      the note (the authored melody is timing-authoritative, and keeps
-      `lyrics.json` and `vocal_pitch.json` mirrored per §7.2); a melisma's
-      extra notes are skipped. Unpaired syllables (talkies) keep the lyric
-      event's own time and run until the next syllable, clamped to
-      [``_UNPAIRED_LYRIC_MIN_D``, ``_UNPAIRED_LYRIC_MAX_D``] — they appear
-      in ``lyrics`` only, which spec §7.2 explicitly allows
-      (`vocal_pitch.notes` MAY be shorter than `lyrics.json`).
-
-    ``audio_offset`` (seconds) shifts every emitted time, same handle as
-    the keys/drums converters. Tempo-map scope per SMF type also matches
-    them (type 2 reads only the involved track's tempo events).
-    """
-    offset = float(audio_offset)
-    if not math.isfinite(offset):
-        raise ValueError(f"audio_offset must be a finite number, got {audio_offset!r}")
-
-    midi = mido.MidiFile(midi_path)
-    midi_type = getattr(midi, "type", 1)
-    scans = _scan_tracks_for_lyrics(midi)
-
-    # ── choose the lyric event stream ────────────────────────────────────
-    lyric_idx = -1
-    best_count = 0
-    for i, scan in enumerate(scans):
-        if len(scan["lyric_events"]) > best_count:
-            lyric_idx = i
-            best_count = len(scan["lyric_events"])
-    if lyric_idx >= 0:
-        toks = _normalize_lyric_tokens(scans[lyric_idx]["lyric_events"])
-    else:
-        # Text-event fallback: vocal-ish tracks only (plus .kar "Words" /
-        # "Soft Karaoke" text tracks). Normalize before counting so a track
-        # of @-metadata can't outscore a real lyric track.
-        toks = []
-        for i, scan in enumerate(scans):
-            if not scan["text_events"]:
-                continue
-            vocal_prog = any(
-                p in _VOCAL_MIDI_PROGRAMS
-                for p in scan["channel_programs"].values()
-            )
-            if not (vocal_prog
-                    or _name_matches(scan["name"], _LYRIC_TEXT_TRACK_HINTS)):
-                continue
-            cand = _normalize_lyric_tokens(scan["text_events"])
-            if len(cand) > len(toks):
-                lyric_idx = i
-                toks = cand
-    if lyric_idx < 0 or not toks:
-        return None
-
-    words = _apply_word_conventions(toks)
-    lyric_tick_to_seconds = _build_tick_to_seconds(midi, lyric_idx)
-
-    # ── pick + time the vocal note pool ──────────────────────────────────
-    picked = _select_vocal_notes(scans, lyric_idx, midi_type)
-    vocal_notes: list[dict] = []
-    if picked is not None:
-        note_idx, pool = picked
-        # Type-2 tracks own independent timelines — time the notes through
-        # their own track's tempo scope (same map as the lyric track for
-        # type 0/1, where tempo is merged across tracks anyway).
-        note_tick_to_seconds = (
-            lyric_tick_to_seconds if note_idx == lyric_idx
-            else _build_tick_to_seconds(midi, note_idx)
-        )
-        for start_tick, end_tick, pitch, _ch in pool:
-            t = note_tick_to_seconds(start_tick)
-            vocal_notes.append({
-                "t": t,
-                "d": max(0.0, note_tick_to_seconds(end_tick) - t),
-                "midi": int(pitch),
-            })
-        vocal_notes.sort(key=lambda n: n["t"])
-
-    # ── pair syllables with notes (greedy, time-ordered) ─────────────────
-    entries: list[dict] = []  # {t, d (None until resolved), w, paired}
-    j = 0
-    for tk, w in zip(toks, words):
-        t_lyric = lyric_tick_to_seconds(tk["tick"])
-        while (j < len(vocal_notes)
-               and vocal_notes[j]["t"] < t_lyric - _LYRIC_PAIR_TOLERANCE_S):
-            j += 1
-        if (j < len(vocal_notes)
-                and vocal_notes[j]["t"] <= t_lyric + _LYRIC_PAIR_TOLERANCE_S):
-            note = vocal_notes[j]
-            j += 1
-            entries.append({
-                "t": note["t"], "d": note["d"], "w": w,
-                "midi": note["midi"], "paired": True,
-            })
-        else:
-            entries.append({"t": t_lyric, "d": None, "w": w, "paired": False})
-
-    # Snapping can nudge a paired syllable past an unpaired neighbour;
-    # sort so both sidecars stay chronological for downstream consumers.
-    entries.sort(key=lambda e: e["t"])
-
-    # Unpaired durations: until the next syllable, clamped. Resolved after
-    # the sort so "next" is the true chronological neighbour.
-    for i, e in enumerate(entries):
-        if e["d"] is None:
-            if i + 1 < len(entries):
-                gap = entries[i + 1]["t"] - e["t"]
-                d = min(gap, _UNPAIRED_LYRIC_MAX_D)
-            else:
-                d = _UNPAIRED_LYRIC_MAX_D
-            e["d"] = max(d, _UNPAIRED_LYRIC_MIN_D)
-
-    lyrics_out = [
-        {"t": round(e["t"] + offset, 3), "d": round(e["d"], 3), "w": e["w"]}
-        for e in entries
-    ]
-    pitch_notes = [
-        {"t": round(e["t"] + offset, 3), "d": round(e["d"], 3),
-         "midi": int(e["midi"])}
-        for e in entries if e["paired"]
-    ]
-
-    return {
-        "lyrics": lyrics_out,
-        "lyrics_source": "authored",
-        "vocal_pitch": (
-            {"version": 1, "notes": pitch_notes} if pitch_notes else None
-        ),
-    }

lib/routers/ws_highway.py

@@ -774,20 +774,29 @@ async def highway_ws(websocket: WebSocket, filename: str, arrangement: int = -1,
         # (Arrangement.tones, populated by the converter), so read it straight
         # off `arr` rather than walking for XML that doesn't exist.
         if is_slop:
-            # `sloppak_tone_changes` builds the (base, sorted changes) pair
-            # from `Arrangement.tones`, skipping non-string names and
-            # non-finite/non-numeric times — unit-tested in test_tones.py.
+            # `sloppak_tone_changes` builds the (base, base_rig, sorted
+            # changes) triple from `Arrangement.tones`, skipping non-string
+            # names, non-finite/non-numeric times, and unusable rig ids —
+            # unit-tested in test_tones.py.
             from tones import sloppak_tone_changes
-            base_name, tone_changes = sloppak_tone_changes(getattr(arr, "tones", None))
+            base_name, base_rig, tone_changes = sloppak_tone_changes(
+                getattr(arr, "tones", None)
+            )
             # Send when there's a base tone OR timed changes — a single-tone
             # arrangement has a base but no switches, and the highway should
             # still be able to show the initial tone.
             if tone_changes or base_name:
-                await websocket.send_json({
+                payload = {
                     "type": "tone_changes",
                     "base": base_name,
                     "data": tone_changes,
-                })
+                }
+                # `base_rig` is additive (feedpak-spec §6.9) — omitted entirely
+                # when the chart binds no rig, so consumers that predate the rig
+                # model see the exact payload they always did.
+                if base_rig:
+                    payload["base_rig"] = base_rig
+                await websocket.send_json(payload)
         else:
             xml_paths = sorted(_xml_walk("*.xml"))
 

lib/sloppak.py

@@ -698,6 +698,14 @@ class LoadedSloppak:
     # absent / unreadable / malformed. Streamed over the highway WS as a
     # `keys` message; consumers (renderers, plugins) read it from there.
     keys: dict | None = None
+    # Parsed `rigs.json` payload (manifest `rigs:` key, spec §7.9) — the pack's
+    # library of engine-agnostic signal chains: effect chains and, since
+    # feedpak 1.18.0, MIDI-voiced sound sources. Arrangements bind rigs to time
+    # by referencing a rig `id` from `tones.base_rig` / `tones.changes[].rig`
+    # (§6.9), which `lib/tones.py` carries onto the wire. None when absent /
+    # unreadable / malformed. Rig objects are kept verbatim — this loader does
+    # not select realizations or apply the `intent.gm` floor.
+    rigs: dict | None = None
     # Sanitized song-level tempo + time-signature maps from `song_timeline.json`
     # (feedpak 1.2.0). `tempos`: [{time, bpm}]; `time_signatures`: [{time, ts}].
     # None when absent/empty. Streamed over the highway WS (`tempos` /
@@ -776,18 +784,117 @@ def _load_drum_tab_file(source_dir: Path, rel: str, label: str) -> dict | None:
     return raw
 
 
+def _load_rigs_file(source_dir: Path, rel: str) -> dict | None:
+    """Load the pack's rig library (manifest `rigs:` key, spec §7.9).
+
+    Returns `{"version": int, "rigs": [...]}` or None. Same permissive posture
+    as every other side-file: missing / unreadable / malformed -> None, never
+    fatal — spec §7.9 is explicit that a rig library a Reader can't use MUST NOT
+    fail the pack.
+
+    Rig objects are kept **verbatim**. Only entries that could never be
+    addressed are dropped — a rig is reachable solely by `id` (from
+    `tones.base_rig` / `changes[].rig`), so a non-dict entry or one without a
+    usable string id is unreferenceable by construction. Everything else,
+    including unknown `role` / `engine` / `kind` values and `ext` namespaces,
+    passes through untouched, because this loader does not interpret rigs:
+    realization selection and the `intent.gm` fallback belong to whatever
+    voices the part.
+    """
+    try:
+        r_path = (source_dir / rel).resolve()
+        r_path.relative_to(source_dir.resolve())
+    except ValueError:
+        log.warning("sloppak: rigs path %r escapes source_dir — skipped", rel)
+        return None
+    except OSError as e:
+        log.warning("sloppak: rigs path resolution failed (%s) — skipped", e)
+        return None
+    if not r_path.exists():
+        return None
+    try:
+        raw = load_json(r_path)
+    except Exception as e:
+        log.warning("sloppak: failed to parse rigs %r: %s", rel, e)
+        return None
+    if not isinstance(raw, dict):
+        log.warning("sloppak: rigs %r ignored — expected dict, got %s",
+                    rel, type(raw).__name__)
+        return None
+    if not isinstance(raw.get("rigs"), list):
+        log.warning("sloppak: rigs %r ignored — 'rigs' must be a list", rel)
+        return None
+
+    clean_rigs: list[dict] = []
+    seen: set[str] = set()
+    for rig in raw["rigs"]:
+        if not isinstance(rig, dict):
+            continue
+        rid = rig.get("id")
+        if not isinstance(rid, str) or not rid.strip():
+            continue
+        # Normalize the library side of the lookup the same way the reference
+        # side is normalized in lib/tones.py — otherwise a pack with padded ids
+        # fails to resolve against a stripped `base_rig` / `rig`.
+        rid = rid.strip()
+        # A duplicate id makes `tones.base_rig` ambiguous, which would surface
+        # as the wrong sound rather than an error. First wins, loudly.
+        if rid in seen:
+            log.warning("sloppak: rigs %r has duplicate rig id %r — later one ignored",
+                        rel, rid)
+            continue
+        seen.add(rid)
+        clean_rigs.append({**rig, "id": rid})
+
+    # int only — a float version (incl. NaN/Inf, which json.loads accepts)
+    # would raise on int(); default rather than abort an optional side-file.
+    _ver = raw.get("version")
+    return {
+        "version": _ver if isinstance(_ver, int) and not isinstance(_ver, bool) else 1,
+        "rigs": clean_rigs,
+    }
+
+
+def _entry_tones(entry: dict) -> dict | None:
+    """A manifest entry's `tones` binding, or None when it doesn't carry one.
+
+    Spec §5.2: a manifest arrangement entry's `tones` overrides the arrangement
+    JSON's `tones` **wholesale** — no field-level merge. This normalizes the
+    "does it carry one" test for both the arrangement path and the drum path.
+
+    An empty dict reads as *absent*, not as "override to silence": it is what a
+    Writer emits by accident, `arrangement_from_wire` already normalizes the
+    in-JSON `{}` to None the same way, and treating it as an override would let
+    a stray empty object silently unbind a part's sound.
+    """
+    tones = entry.get("tones")
+    return tones if isinstance(tones, dict) and tones else None
+
+
 def _resolve_drum_parts(
     source_dir: Path,
     drum_tab_rel: object,
     drum_tab_data: dict | None,
     drum_pointer_entries: list[dict],
+    drum_tones: dict | None = None,
 ) -> tuple[dict | None, list[dict] | None]:
-    """Resolve drum pointers into a primary-first list with unique ids."""
+    """Resolve drum pointers into a primary-first list with unique ids.
+
+    Also binds each part's sound (feedpak 1.18.0). The precedence mirrors the
+    `drum_tab` alias rule this function already implements: a `type: drums`
+    entry's own `tones` wins for that part, and the song-level `drum_tones` is
+    the fallback for the **primary** part only. A Reader MUST NOT apply both to
+    the same part (spec §5.1/§5.2), which is why the primary picks one or the
+    other here rather than merging them.
+    """
     if drum_tab_data is None and not drum_pointer_entries:
         return drum_tab_data, None
 
     primary_id = "drums"
     primary_name = None
+    # The primary's own binding, lifted from its alias pointer entry when it has
+    # one. Stays None if no entry claims the primary — `drum_tones` fills in.
+    primary_tones = None
     extra_parts: list[dict] = []
     seen_rels: set[str] = set()
     # Use the same canonical, traversal-safe identity as zip member lookup so
@@ -811,6 +918,11 @@ def _resolve_drum_parts(
                 primary_id = entry_id
             if entry_name:
                 primary_name = entry_name
+            # This entry IS the primary (an alias pointer at the same file), so
+            # its binding is the primary's — and it outranks `drum_tones`.
+            _alias_tones = _entry_tones(entry)
+            if _alias_tones is not None:
+                primary_tones = _alias_tones
             continue
         tab = _load_drum_tab_file(source_dir, rel, f"drum part {entry_id or rel}")
         if tab is None:
@@ -821,6 +933,9 @@ def _resolve_drum_parts(
             "name": entry_name
                 or (tab_name if isinstance(tab_name, str) and tab_name else "Drums"),
             "drum_tab": tab,
+            # Non-primary parts bind through their own entry only; `drum_tones`
+            # is explicitly the primary's fallback, never theirs.
+            "tones": _entry_tones(entry),
         })
 
     parts: list[dict] = []
@@ -829,7 +944,14 @@ def _resolve_drum_parts(
         if primary_name is None:
             tab_name = drum_tab_data.get("name")
             primary_name = tab_name if isinstance(tab_name, str) and tab_name else "Drums"
-        parts.append({"id": primary_id, "name": primary_name, "drum_tab": drum_tab_data})
+        parts.append({
+            "id": primary_id,
+            "name": primary_name,
+            "drum_tab": drum_tab_data,
+            # Entry `tones` takes precedence; `drum_tones` is the fallback. One
+            # or the other, never both on the same part (spec §5.1).
+            "tones": primary_tones if primary_tones is not None else drum_tones,
+        })
         used_ids.add(primary_id)
 
     next_generated_id = 2
@@ -948,6 +1070,14 @@ def load_song(
             # _finite_float keeps a malformed manifest NaN/Infinity from
             # poisoning the song_info JSON (same guard as the wire path).
             arr.cent_offset = _finite_float(entry["centOffset"])
+        # `tones` overrides WHOLESALE, unlike the field-level overrides above:
+        # the entry's object replaces the arrangement JSON's entirely, with no
+        # per-field merge (spec §5.2). A Writer SHOULD NOT emit both, but when
+        # one does, a half-merged sound — this pack's base with that pack's
+        # changes — would be worse than either source alone.
+        _entry_tone_block = _entry_tones(entry)
+        if _entry_tone_block is not None:
+            arr.tones = _entry_tone_block
 
         # Beats/sections can live on the arrangement itself in the wire format.
         # If the manifest-level arrangement JSON carries them, pull them onto
@@ -1020,8 +1150,15 @@ def load_song(
 
     # Keep the dense compatibility logic independently testable and guarantee
     # ids are unique before the highway exposes them as selectors.
+    # Top-level `drum_tones` (spec §5.1) binds the song-level drum part — the
+    # fallback for packs without `type: drums` arrangements. Same shape as an
+    # arrangement entry's `tones`; `_resolve_drum_parts` owns the precedence.
+    _raw_drum_tones = manifest.get("drum_tones")
+    drum_tones_data = _raw_drum_tones if isinstance(_raw_drum_tones, dict) and _raw_drum_tones else None
+
     drum_tab_data, drum_parts = _resolve_drum_parts(
         source_dir, drum_tab_rel, drum_tab_data, drum_pointer_entries,
+        drum_tones_data,
     )
 
     # Drum-only sloppak: every GP track was percussion, so it ships a
@@ -1325,6 +1462,14 @@ def load_song(
                         "events": clean_events,
                     }
 
+    # Optional rigs.json — the pack's rig library (manifest `rigs:` key,
+    # spec §7.9). Loaded here so the highway WS can hand it to whatever voices
+    # the part; the bindings that reference it ride the arrangement's `tones`.
+    rigs_data: dict | None = None
+    rigs_rel = manifest.get("rigs")
+    if isinstance(rigs_rel, str) and rigs_rel:
+        rigs_data = _load_rigs_file(source_dir, rigs_rel)
+
     _fpv = manifest.get("feedpak_version")
     # The pack's full mix. Normally the RESERVED `full` stem partitioned out
     # above (spec §5.3) — no path work needed, it was validated with the other
@@ -1355,6 +1500,7 @@ def load_song(
         tempos=tempos_data,
         time_signatures=time_sigs_data,
         keys=keys_data,
+        rigs=rigs_data,
         notation_by_id=notation_by_id_data,
         arrangement_ids=arrangement_ids_acc,
         full_mix=full_mix_data,

lib/tones.py

@@ -32,20 +32,29 @@ def tokens(s: str) -> set[str]:
     return {t for t in re.split(r"[^a-z0-9]+", (s or "").lower()) if t}
 
 
-def sloppak_tone_changes(arr_tones) -> tuple[str, list[dict]]:
+def sloppak_tone_changes(arr_tones) -> tuple[str, str, list[dict]]:
     """Build the highway tone-change payload from an arrangement's tone block.
 
     Given ``Arrangement.tones`` (the dict embedded in the sloppak, or ``None``),
-    returns ``(base, changes)`` where ``base`` is the initial tone name and
-    ``changes`` is a time-sorted ``[{"t", "name"}]`` list. Non-string names,
-    non-dict entries, and non-numeric / non-finite times are skipped — a
-    hand-edited or third-party sloppak must not crash the highway WebSocket
-    or emit NaN/inf (which the client's ``JSON.parse`` rejects).
+    returns ``(base, base_rig, changes)`` where ``base`` is the initial tone
+    name, ``base_rig`` is the ``rigs.json`` rig id bound to it (feedpak-spec
+    §6.9; ``""`` when absent), and ``changes`` is a time-sorted
+    ``[{"t", "name", "rig"?}]`` list. Non-string names, non-dict entries, and
+    non-numeric / non-finite times are skipped — a hand-edited or third-party
+    sloppak must not crash the highway WebSocket or emit NaN/inf (which the
+    client's ``JSON.parse`` rejects).
+
+    ``rig`` / ``base_rig`` are carried through but NOT resolved against
+    ``rigs.json`` here: this builder only preserves the binding the chart
+    declared. Realization selection and the ``intent.gm`` fallback (§7.9) belong
+    to the consumer that actually voices the part.
     """
     if not isinstance(arr_tones, dict):
-        return "", []
+        return "", "", []
     base_val = arr_tones.get("base", "")
     base = base_val.strip() if isinstance(base_val, str) else ""
+    base_rig_val = arr_tones.get("base_rig", "")
+    base_rig = base_rig_val.strip() if isinstance(base_rig_val, str) else ""
 
     changes: list[dict] = []
     raw_changes = arr_tones.get("changes")
@@ -65,6 +74,13 @@ def sloppak_tone_changes(arr_tones) -> tuple[str, list[dict]]:
             continue
         if not math.isfinite(t):
             continue
-        changes.append({"t": round(t, 3), "name": name})
+        change = {"t": round(t, 3), "name": name}
+        # ponytail: `rig` only when it's a usable id — a non-string or blank
+        # value is dropped rather than forwarded, so a consumer can treat
+        # presence of the key as "this change binds a rig".
+        rig = c.get("rig")
+        if isinstance(rig, str) and rig.strip():
+            change["rig"] = rig.strip()
+        changes.append(change)
     changes.sort(key=lambda x: x["t"])
-    return base, changes
+    return base, base_rig, changes

tests/test_midi_lyrics.py

@@ -1,282 +0,0 @@
-"""Tests for lib/midi_import.py — extract_midi_lyrics (lyrics + vocal melody).
-
-Synthetic mido.MidiFile objects are built in-memory and saved to tmp_path,
-same style as test_midi_import.py.
-
-Covers:
-  - Lyric (0x05) events on a vocal track → lyrics.json + vocal_pitch.json payloads
-  - lyric/note pairing snaps t/d to the note; midi pitch carried through
-  - lyrics with no identifiable vocal track → lyrics payload only
-  - no lyric events at all → None (import behavior unchanged)
-  - .kar '/' line-break prefixes → spec trailing '+' on the previous syllable
-  - .kar '-' hyphen joins pass through untouched
-  - space-delimited syllable streams gain '-' joins
-  - '@'-metadata tokens dropped; Text-event (0x01) fallback on vocal-ish tracks
-  - Text events on non-vocal tracks are NOT treated as lyrics
-  - unpaired lyric durations run to the next syllable, capped at 2.0 s
-  - format-0 mixed-channel file pairs only the vocal-program channel
-  - vocal GM program (52-54 / 85-87) detection without a track name
-  - audio_offset applied to both payloads
-"""
-
-import pytest
-import mido
-
-from midi_import import extract_midi_lyrics
-
-
-TPB = 480  # ticks per beat; default 120 BPM → 480 ticks = 0.5 s
-
-
-def _save(mid: mido.MidiFile, tmp_path, name: str = "test.mid") -> str:
-    p = tmp_path / name
-    mid.save(str(p))
-    return str(p)
-
-
-def _vocal_file(tmp_path, *, track_name="Vocals", program=None, meta="lyrics",
-                syllables=("Hel-", "lo", "world")):
-    """Type-1 file: conductor + one melody track carrying notes with a lyric
-    event at each note-on. Notes: 60, 62, 64, each one beat (0.5 s) long,
-    back to back."""
-    mid = mido.MidiFile(type=1, ticks_per_beat=TPB)
-    conductor = mido.MidiTrack()
-    mid.tracks.append(conductor)
-    conductor.append(mido.MetaMessage("set_tempo", tempo=500000, time=0))
-
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    if track_name:
-        tr.append(mido.MetaMessage("track_name", name=track_name, time=0))
-    if program is not None:
-        tr.append(mido.Message("program_change", channel=0, program=program, time=0))
-    for i, syl in enumerate(syllables):
-        tr.append(mido.MetaMessage(meta, text=syl, time=0))
-        tr.append(mido.Message("note_on", channel=0, note=60 + 2 * i,
-                               velocity=90, time=0))
-        tr.append(mido.Message("note_off", channel=0, note=60 + 2 * i,
-                               velocity=0, time=TPB))
-    return _save(mid, tmp_path)
-
-
-# ── both sidecars from a lyric+vocal-track file ──────────────────────────────
-
-def test_vocal_track_emits_both_payloads(tmp_path):
-    result = extract_midi_lyrics(_vocal_file(tmp_path))
-    assert result is not None
-    assert result["lyrics_source"] == "authored"
-
-    lyr = result["lyrics"]
-    assert [e["w"] for e in lyr] == ["Hel-", "lo", "world"]
-    assert [e["t"] for e in lyr] == pytest.approx([0.0, 0.5, 1.0])
-    # Paired syllables snap d to the note duration (1 beat = 0.5 s).
-    assert [e["d"] for e in lyr] == pytest.approx([0.5, 0.5, 0.5])
-
-    vp = result["vocal_pitch"]
-    assert vp is not None
-    assert vp["version"] == 1
-    assert [n["midi"] for n in vp["notes"]] == [60, 62, 64]
-    # vocal_pitch t/d mirror the matching lyrics entries (spec §7.2).
-    assert [(n["t"], n["d"]) for n in vp["notes"]] == \
-        [(e["t"], e["d"]) for e in lyr]
-
-
-def test_vocal_program_detection_without_name(tmp_path):
-    """GM program 53 (Voice Oohs) marks the track vocal even with no name."""
-    path = _vocal_file(tmp_path, track_name="", program=53)
-    result = extract_midi_lyrics(path)
-    assert result is not None
-    assert result["vocal_pitch"] is not None
-    assert [n["midi"] for n in result["vocal_pitch"]["notes"]] == [60, 62, 64]
-
-
-# ── lyrics-only fallbacks ────────────────────────────────────────────────────
-
-def test_no_vocal_track_emits_lyrics_only(tmp_path):
-    """Lyric events on a noteless track + only a piano note track → the
-    lyrics payload is emitted but vocal_pitch is None (talkies path)."""
-    mid = mido.MidiFile(type=1, ticks_per_beat=TPB)
-    conductor = mido.MidiTrack()
-    mid.tracks.append(conductor)
-    conductor.append(mido.MetaMessage("set_tempo", tempo=500000, time=0))
-
-    words = mido.MidiTrack()
-    mid.tracks.append(words)
-    words.append(mido.MetaMessage("lyrics", text="Hello ", time=0))
-    words.append(mido.MetaMessage("lyrics", text="there ", time=TPB))
-
-    piano = mido.MidiTrack()
-    mid.tracks.append(piano)
-    piano.append(mido.MetaMessage("track_name", name="Piano", time=0))
-    piano.append(mido.Message("program_change", channel=0, program=0, time=0))
-    piano.append(mido.Message("note_on", channel=0, note=48, velocity=90, time=0))
-    piano.append(mido.Message("note_off", channel=0, note=48, velocity=0, time=TPB))
-
-    result = extract_midi_lyrics(_save(mid, tmp_path))
-    assert result is not None
-    assert [e["w"] for e in result["lyrics"]] == ["Hello", "there"]
-    assert result["vocal_pitch"] is None
-
-
-def test_no_lyrics_returns_none(tmp_path):
-    """A file without lyric events changes nothing — extraction reports None."""
-    mid = mido.MidiFile(type=0, ticks_per_beat=TPB)
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    tr.append(mido.Message("note_on", channel=0, note=60, velocity=90, time=0))
-    tr.append(mido.Message("note_off", channel=0, note=60, velocity=0, time=TPB))
-
-    assert extract_midi_lyrics(_save(mid, tmp_path)) is None
-
-
-def test_unpaired_duration_next_event_capped_at_2s(tmp_path):
-    """Unpaired lyric entries last until the next syllable, capped at 2.0 s."""
-    mid = mido.MidiFile(type=1, ticks_per_beat=TPB)
-    conductor = mido.MidiTrack()
-    mid.tracks.append(conductor)
-    conductor.append(mido.MetaMessage("set_tempo", tempo=500000, time=0))
-
-    words = mido.MidiTrack()
-    mid.tracks.append(words)
-    words.append(mido.MetaMessage("lyrics", text="one ", time=0))
-    words.append(mido.MetaMessage("lyrics", text="two ", time=TPB))       # +0.5 s
-    words.append(mido.MetaMessage("lyrics", text="three ", time=TPB * 8))  # +4.0 s
-
-    result = extract_midi_lyrics(_save(mid, tmp_path))
-    lyr = result["lyrics"]
-    assert lyr[0]["d"] == pytest.approx(0.5)   # gap to next syllable
-    assert lyr[1]["d"] == pytest.approx(2.0)   # 4.0 s gap capped
-    assert lyr[2]["d"] == pytest.approx(2.0)   # last entry: cap value
-
-
-# ── .kar conventions ─────────────────────────────────────────────────────────
-
-def test_kar_slash_line_break_maps_to_plus(tmp_path):
-    """A '/' prefix on a syllable marks the END of the previous line — the
-    previous syllable gains the spec's trailing '+'."""
-    path = _vocal_file(
-        tmp_path, syllables=("Hel-", "lo", "/world"))
-    result = extract_midi_lyrics(path)
-    words = [e["w"] for e in result["lyrics"]]
-    assert words == ["Hel-", "lo+", "world"]
-
-
-def test_kar_backslash_paragraph_break_maps_to_plus(tmp_path):
-    path = _vocal_file(tmp_path, syllables=("one", "\\two", "three"))
-    words = [e["w"] for e in extract_midi_lyrics(path)["lyrics"]]
-    assert words == ["one+", "two", "three"]
-
-
-def test_kar_hyphen_joins_pass_through(tmp_path):
-    """.kar hyphen suffixes already ARE the spec join marker — untouched,
-    and no extra '-' is synthesized onto hyphenless word-final syllables."""
-    path = _vocal_file(tmp_path, syllables=("beau-", "ti-", "ful", "day"))
-    words = [e["w"] for e in extract_midi_lyrics(path)["lyrics"]]
-    assert words == ["beau-", "ti-", "ful", "day"]
-
-
-def test_space_delimited_stream_gains_hyphen_joins(tmp_path):
-    """Space-delimited Lyric streams ('Hel' 'lo ' 'world') carry word
-    boundaries in whitespace — mid-word syllables gain the '-' join."""
-    path = _vocal_file(tmp_path, syllables=("Hel", "lo ", "world "))
-    words = [e["w"] for e in extract_midi_lyrics(path)["lyrics"]]
-    assert words == ["Hel-", "lo", "world"]
-
-
-def test_newline_in_lyric_event_ends_line(tmp_path):
-    path = _vocal_file(tmp_path, syllables=("one \n", "two ", "three "))
-    words = [e["w"] for e in extract_midi_lyrics(path)["lyrics"]]
-    assert words == ["one+", "two", "three"]
-
-
-# ── Text-event (0x01) fallback ───────────────────────────────────────────────
-
-def test_text_event_fallback_on_vocal_track(tmp_path):
-    """With no 0x05 events anywhere, Text events on a vocal-ish track are
-    accepted as lyrics; '@'-prefixed .kar metadata tokens are dropped."""
-    mid = mido.MidiFile(type=1, ticks_per_beat=TPB)
-    conductor = mido.MidiTrack()
-    mid.tracks.append(conductor)
-    conductor.append(mido.MetaMessage("set_tempo", tempo=500000, time=0))
-
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    tr.append(mido.MetaMessage("track_name", name="Melody", time=0))
-    tr.append(mido.MetaMessage("text", text="@KMIDI KARAOKE FILE", time=0))
-    tr.append(mido.MetaMessage("text", text="@T A Song", time=0))
-    for i, syl in enumerate(("Some ", "words ")):
-        tr.append(mido.MetaMessage("text", text=syl, time=0))
-        tr.append(mido.Message("note_on", channel=0, note=64 + i, velocity=90,
-                               time=0))
-        tr.append(mido.Message("note_off", channel=0, note=64 + i, velocity=0,
-                               time=TPB))
-
-    result = extract_midi_lyrics(_save(mid, tmp_path))
-    assert result is not None
-    assert [e["w"] for e in result["lyrics"]] == ["Some", "words"]
-    assert [n["midi"] for n in result["vocal_pitch"]["notes"]] == [64, 65]
-
-
-def test_text_events_on_non_vocal_track_ignored(tmp_path):
-    """Text events on a plain instrument track (copyright notices, markers)
-    are not lyrics — extraction returns None."""
-    mid = mido.MidiFile(type=1, ticks_per_beat=TPB)
-    conductor = mido.MidiTrack()
-    mid.tracks.append(conductor)
-    conductor.append(mido.MetaMessage("set_tempo", tempo=500000, time=0))
-
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    tr.append(mido.MetaMessage("track_name", name="Guitar", time=0))
-    tr.append(mido.MetaMessage("text", text="Copyright 2026", time=0))
-    tr.append(mido.Message("note_on", channel=0, note=52, velocity=90, time=0))
-    tr.append(mido.Message("note_off", channel=0, note=52, velocity=0, time=TPB))
-
-    assert extract_midi_lyrics(_save(mid, tmp_path)) is None
-
-
-# ── format-0 channel isolation ───────────────────────────────────────────────
-
-def test_format0_pairs_only_vocal_program_channel(tmp_path):
-    """Format-0 file mixing a vocal-program channel with an accompaniment
-    channel: only the vocal channel's notes feed vocal_pitch."""
-    mid = mido.MidiFile(type=0, ticks_per_beat=TPB)
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    tr.append(mido.Message("program_change", channel=0, program=53, time=0))  # Voice Oohs
-    tr.append(mido.Message("program_change", channel=1, program=0, time=0))   # Piano
-    # Simultaneous piano note that must NOT be paired.
-    tr.append(mido.Message("note_on", channel=1, note=40, velocity=90, time=0))
-    tr.append(mido.MetaMessage("lyrics", text="la ", time=0))
-    tr.append(mido.Message("note_on", channel=0, note=67, velocity=90, time=0))
-    tr.append(mido.Message("note_off", channel=0, note=67, velocity=0, time=TPB))
-    tr.append(mido.Message("note_off", channel=1, note=40, velocity=0, time=0))
-
-    result = extract_midi_lyrics(_save(mid, tmp_path))
-    assert result is not None
-    assert [n["midi"] for n in result["vocal_pitch"]["notes"]] == [67]
-
-
-def test_format0_without_vocal_channel_is_lyrics_only(tmp_path):
-    """Format-0 with lyrics but no vocal program/name: the merged note soup
-    cannot be trusted as a melody — lyrics.json only."""
-    mid = mido.MidiFile(type=0, ticks_per_beat=TPB)
-    tr = mido.MidiTrack()
-    mid.tracks.append(tr)
-    tr.append(mido.Message("program_change", channel=0, program=0, time=0))
-    tr.append(mido.MetaMessage("lyrics", text="la ", time=0))
-    tr.append(mido.Message("note_on", channel=0, note=60, velocity=90, time=0))
-    tr.append(mido.Message("note_off", channel=0, note=60, velocity=0, time=TPB))
-
-    result = extract_midi_lyrics(_save(mid, tmp_path))
-    assert result is not None
-    assert len(result["lyrics"]) == 1
-    assert result["vocal_pitch"] is None
-
-
-# ── audio_offset ─────────────────────────────────────────────────────────────
-
-def test_audio_offset_applied_to_both_payloads(tmp_path):
-    result = extract_midi_lyrics(_vocal_file(tmp_path), audio_offset=1.5)
-    assert result["lyrics"][0]["t"] == pytest.approx(1.5)
-    assert result["vocal_pitch"]["notes"][0]["t"] == pytest.approx(1.5)

tests/test_sloppak_rigs_load.py

@@ -0,0 +1,207 @@
+"""End-to-end test for the sloppak loader recognising a `rigs:` manifest key
+(rigs.json — the pack-level library of engine-agnostic rigs, spec §7.9) and
+surfacing the payload on the LoadedSloppak.
+
+The governing posture: rig objects pass through VERBATIM. This loader does not
+select realizations or apply the `intent.gm` floor — it only makes the library
+addressable by `id`, which is what `tones.base_rig` / `tones.changes[].rig`
+reference."""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import yaml
+
+import sloppak as sloppak_mod
+
+
+def _write_dir_sloppak(root: Path, manifest_extras: dict, rigs_payload) -> Path:
+    """Minimal directory-form sloppak; writes rigs.json when a payload is given.
+
+    Unique filename per test (tmp_path leaf) so the module-level
+    resolve_source_dir cache isn't poisoned across tests."""
+    pak = root / f"{root.name}.sloppak"
+    pak.mkdir()
+    arr_dir = pak / "arrangements"
+    arr_dir.mkdir()
+    arr = {
+        "name": "Lead", "tuning": [0, 0, 0, 0, 0, 0], "capo": 0,
+        "notes": [], "chords": [], "anchors": [], "handshapes": [],
+        "templates": [], "beats": [], "sections": [],
+    }
+    (arr_dir / "lead.json").write_text(json.dumps(arr))
+
+    manifest = {
+        "title": "Test", "artist": "Tester", "album": "", "year": 2026,
+        "duration": 10.0,
+        "arrangements": [{"id": "lead", "name": "Lead", "file": "arrangements/lead.json"}],
+        "stems": [{"id": "full", "file": "stems/full.ogg", "default": True}],
+    }
+    manifest.update(manifest_extras)
+    (pak / "manifest.yaml").write_text(yaml.safe_dump(manifest, sort_keys=False))
+
+    if rigs_payload is not None:
+        (pak / "rigs.json").write_text(json.dumps(rigs_payload))
+    return pak
+
+
+def _load(pak_path: Path, tmp_path: Path):
+    dlc_root = pak_path.parent
+    cache = tmp_path / "cache"
+    cache.mkdir()
+    return sloppak_mod.load_song(pak_path.name, dlc_root, cache)
+
+
+# ── Happy path ───────────────────────────────────────────────────────────────
+
+def test_load_song_attaches_rigs_when_manifest_opts_in(tmp_path: Path):
+    """A source rig (spec §7.9 1.18.0) survives the load intact — including the
+    `soundfont` realization and the `intent.gm` floor a consumer needs to voice
+    the part."""
+    payload = {
+        "version": 1,
+        "rigs": [
+            {
+                "id": "grand-piano",
+                "name": "Grand Piano",
+                "instrument": "keys",
+                "blocks": [
+                    {
+                        "role": "source",
+                        "name": "Concert Grand",
+                        "intent": {"kind": "instrument", "gm": {"program": 0}},
+                        "realizations": [
+                            {"engine": "soundfont", "format": "sf2",
+                             "ref": "sounds/grand.sf2", "bank": 0, "program": 0},
+                        ],
+                    },
+                ],
+            },
+        ],
+    }
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, payload)
+    loaded = _load(pak, tmp_path)
+    assert loaded.rigs is not None
+    assert loaded.rigs["version"] == 1
+    assert loaded.rigs["rigs"] == payload["rigs"]
+
+
+def test_load_song_rigs_absent_without_manifest_key(tmp_path: Path):
+    """The file alone must not opt a pack in — the manifest is the opt-in
+    (spec §9.1, "manifest opt-in, file off to the side")."""
+    pak = _write_dir_sloppak(tmp_path, {}, {"version": 1, "rigs": []})
+    assert _load(pak, tmp_path).rigs is None
+
+
+# ── Verbatim passthrough ─────────────────────────────────────────────────────
+
+def test_load_song_preserves_unknown_rig_content(tmp_path: Path):
+    """Unknown `role` / `engine` / `kind` values and `ext` namespaces MUST
+    survive (spec §7.9) — core does not interpret rigs, so it must not prune
+    what a newer writer or a plugin put there."""
+    payload = {
+        "version": 2,
+        "rigs": [
+            {
+                "id": "future-rig",
+                "blocks": [
+                    {"role": "quantum-flux", "intent": {"kind": "not-yet-invented"},
+                     "realizations": [{"engine": "some-future-engine", "ref": "x.bin"}],
+                     "ext": {"vendor.custom": {"anything": [1, 2, 3]}}},
+                ],
+                "graph": {"nodes": ["input", "output"], "edges": [["input", "output"]]},
+                "ext": {"vendor.rig": "kept"},
+            },
+        ],
+    }
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, payload)
+    loaded = _load(pak, tmp_path)
+    assert loaded.rigs["version"] == 2
+    assert loaded.rigs["rigs"] == payload["rigs"]
+
+
+# ── Addressability ───────────────────────────────────────────────────────────
+
+def test_load_song_drops_unaddressable_rigs_and_normalizes_ids(tmp_path: Path):
+    """A rig is reachable only by `id`, so entries without a usable one are
+    unreferenceable by construction. Ids are stripped to match the reference
+    side, which lib/tones.py strips before it reaches the wire."""
+    payload = {
+        "rigs": [
+            "not-a-dict",
+            {"name": "no id at all"},
+            {"id": "", "name": "blank id"},
+            {"id": "   ", "name": "whitespace id"},
+            {"id": 7, "name": "non-string id"},
+            {"id": "  padded-rig  ", "name": "Padded"},
+            {"id": "plain-rig", "name": "Plain"},
+        ],
+    }
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, payload)
+    loaded = _load(pak, tmp_path)
+    assert [r["id"] for r in loaded.rigs["rigs"]] == ["padded-rig", "plain-rig"]
+    # Everything except the normalized id is untouched.
+    assert loaded.rigs["rigs"][0]["name"] == "Padded"
+    # `version` defaults when the file omits it.
+    assert loaded.rigs["version"] == 1
+
+
+def test_load_song_first_rig_wins_on_duplicate_id(tmp_path: Path):
+    """A duplicate id makes `tones.base_rig` ambiguous, which would surface as
+    the wrong sound rather than an error."""
+    payload = {
+        "rigs": [
+            {"id": "dupe", "name": "First"},
+            {"id": "dupe", "name": "Second"},
+            {"id": " dupe ", "name": "Third, padded into a collision"},
+        ],
+    }
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, payload)
+    loaded = _load(pak, tmp_path)
+    assert len(loaded.rigs["rigs"]) == 1
+    assert loaded.rigs["rigs"][0]["name"] == "First"
+
+
+# ── Permissive posture (spec §7.9: never fail the pack) ──────────────────────
+
+def test_load_song_survives_malformed_rigs(tmp_path: Path):
+    """Malformed / missing / traversing rig libraries disable rigs, never the
+    pack — the song itself must still load."""
+    cases = [
+        {"version": 1, "rigs": "not-a-list"},   # wrong `rigs` type
+        ["top-level-not-a-dict"],               # wrong document type
+        {"version": 1},                         # no `rigs` key at all
+    ]
+    for i, payload in enumerate(cases):
+        sub = tmp_path / f"case{i}"
+        sub.mkdir()
+        pak = _write_dir_sloppak(sub, {"rigs": "rigs.json"}, payload)
+        loaded = _load(pak, sub)
+        assert loaded.rigs is None, f"case {i} should disable rigs"
+        assert loaded.song is not None, f"case {i} must not fail the pack"
+
+
+def test_load_song_survives_unparseable_rigs(tmp_path: Path):
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, None)
+    (pak / "rigs.json").write_text("{ not json at all ")
+    loaded = _load(pak, tmp_path)
+    assert loaded.rigs is None
+    assert loaded.song is not None
+
+
+def test_load_song_survives_missing_rigs_file(tmp_path: Path):
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "rigs.json"}, None)
+    loaded = _load(pak, tmp_path)
+    assert loaded.rigs is None
+    assert loaded.song is not None
+
+
+def test_load_song_rejects_traversing_rigs_path(tmp_path: Path):
+    """A crafted manifest must not read outside the pack."""
+    (tmp_path / "outside.json").write_text(json.dumps({"rigs": [{"id": "leaked"}]}))
+    pak = _write_dir_sloppak(tmp_path, {"rigs": "../outside.json"}, None)
+    loaded = _load(pak, tmp_path)
+    assert loaded.rigs is None
+    assert loaded.song is not None

tests/test_sloppak_tones_precedence.py

@@ -0,0 +1,230 @@
+"""Loader coverage for the manifest-vs-in-JSON `tones` precedence cascade
+(feedpak 1.18.0, spec §5.1 / §5.2).
+
+Two rules, both about *which* sound binding wins, neither about interpreting it:
+
+  - A manifest arrangement entry's `tones` replaces the arrangement JSON's
+    `tones` **WHOLESALE** — no field-level merge. A half-merged block (this
+    source's `base` with that source's `changes`) would be a sound nobody
+    authored, so the two never blend.
+  - Top-level `drum_tones` binds the song-level (primary) drum part and is the
+    fallback; a `type: drums` entry's own `tones` takes precedence, and a
+    Reader MUST NOT apply both to the same part.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import yaml
+
+import sloppak as sloppak_mod
+
+
+IN_JSON_TONES = {
+    "base": "In-JSON Clean",
+    "base_rig": "injson-clean",
+    "changes": [{"t": 5.0, "name": "In-JSON Lead", "rig": "injson-lead"}],
+}
+ENTRY_TONES = {
+    "base": "Entry Grand",
+    "base_rig": "entry-grand",
+    "changes": [{"t": 9.0, "name": "Entry Rhodes", "rig": "entry-rhodes"}],
+}
+
+
+def _tab(name: str) -> dict:
+    return {
+        "version": 1,
+        "name": name,
+        "kit": [{"id": "kick", "name": "Kick"}],
+        "hits": [{"t": 1.0, "p": "kick", "v": 100}],
+    }
+
+
+def _write_pak(root: Path, manifest_extras: dict, arr_tones: dict | None = None,
+               files: dict[str, dict] | None = None) -> Path:
+    """Directory-form sloppak with one Lead arrangement, optionally carrying an
+    in-JSON `tones` block, plus any extra files."""
+    pak = root / f"{root.name}.sloppak"
+    pak.mkdir()
+    arr_dir = pak / "arrangements"
+    arr_dir.mkdir()
+    arr = {
+        "name": "Lead", "tuning": [0, 0, 0, 0, 0, 0], "capo": 0,
+        "notes": [], "chords": [], "anchors": [], "handshapes": [],
+        "templates": [], "beats": [], "sections": [],
+    }
+    if arr_tones is not None:
+        arr["tones"] = arr_tones
+    (arr_dir / "lead.json").write_text(json.dumps(arr))
+
+    manifest = {
+        "title": "Test", "artist": "Tester", "album": "", "year": 2026,
+        "duration": 10.0,
+        "arrangements": [{"id": "lead", "name": "Lead", "file": "arrangements/lead.json"}],
+        "stems": [{"id": "full", "file": "stems/full.ogg", "default": True}],
+    }
+    manifest.update(manifest_extras)
+    (pak / "manifest.yaml").write_text(yaml.safe_dump(manifest, sort_keys=False))
+    for rel, payload in (files or {}).items():
+        (pak / rel).write_text(json.dumps(payload))
+    return pak
+
+
+def _load(pak_path: Path, tmp_path: Path):
+    cache = tmp_path / "cache"
+    cache.mkdir()
+    return sloppak_mod.load_song(pak_path.name, pak_path.parent, cache)
+
+
+# ── Arrangement entry vs in-JSON (§5.2) ──────────────────────────────────────
+
+def test_entry_tones_replaces_in_json_wholesale(tmp_path: Path):
+    """The entry object replaces the in-JSON one entirely — no key survives
+    from the loser, not even ones the winner doesn't define."""
+    entry_tones = {"base": "Entry Only"}          # no base_rig, no changes
+    pak = _write_pak(
+        tmp_path,
+        {"arrangements": [{"id": "lead", "name": "Lead",
+                           "file": "arrangements/lead.json",
+                           "tones": entry_tones}]},
+        arr_tones=IN_JSON_TONES,
+    )
+    arr = _load(pak, tmp_path).song.arrangements[0]
+    assert arr.tones == entry_tones
+    # The in-JSON `base_rig` and `changes` must NOT have been merged in.
+    assert "base_rig" not in arr.tones
+    assert "changes" not in arr.tones
+
+
+def test_in_json_tones_survive_when_entry_has_none(tmp_path: Path):
+    pak = _write_pak(tmp_path, {}, arr_tones=IN_JSON_TONES)
+    assert _load(pak, tmp_path).song.arrangements[0].tones == IN_JSON_TONES
+
+
+def test_empty_entry_tones_is_absent_not_an_override(tmp_path: Path):
+    """`{}` reads as "didn't specify", not "override to silence" — otherwise a
+    stray empty object silently unbinds the part's sound."""
+    pak = _write_pak(
+        tmp_path,
+        {"arrangements": [{"id": "lead", "name": "Lead",
+                           "file": "arrangements/lead.json", "tones": {}}]},
+        arr_tones=IN_JSON_TONES,
+    )
+    assert _load(pak, tmp_path).song.arrangements[0].tones == IN_JSON_TONES
+
+
+def test_malformed_entry_tones_is_ignored(tmp_path: Path):
+    """A non-dict `tones` must not override, and must not crash the load."""
+    pak = _write_pak(
+        tmp_path,
+        {"arrangements": [{"id": "lead", "name": "Lead",
+                           "file": "arrangements/lead.json",
+                           "tones": ["not", "a", "dict"]}]},
+        arr_tones=IN_JSON_TONES,
+    )
+    assert _load(pak, tmp_path).song.arrangements[0].tones == IN_JSON_TONES
+
+
+def test_entry_tones_binds_a_notation_only_arrangement(tmp_path: Path):
+    """§5.2: entry `tones` is available whether or not the arrangement has a
+    `file` — a keys part is a notation-only entry, and binding its sound is the
+    whole point of the 1.18.0 work."""
+    notation = {"version": 1, "measures": []}
+    pak = _write_pak(
+        tmp_path,
+        {"arrangements": [{"id": "keys", "name": "Keys",
+                           "notation": "notation_keys.json",
+                           "tones": ENTRY_TONES}]},
+        files={"notation_keys.json": notation},
+    )
+    arr = _load(pak, tmp_path).song.arrangements[0]
+    assert arr.name == "Keys"
+    assert arr.tones == ENTRY_TONES
+
+
+# ── drum_tones vs entry tones (§5.1) ─────────────────────────────────────────
+
+def test_drum_tones_binds_the_primary_part(tmp_path: Path):
+    pak = _write_pak(
+        tmp_path,
+        {"drum_tab": "drum_tab.json", "drum_tones": ENTRY_TONES},
+        files={"drum_tab.json": _tab("Drums")},
+    )
+    parts = _load(pak, tmp_path).drum_parts
+    assert len(parts) == 1
+    assert parts[0]["tones"] == ENTRY_TONES
+
+
+def test_entry_tones_outrank_drum_tones_on_the_primary(tmp_path: Path):
+    """An alias pointer entry naming the same file IS the primary, so its own
+    binding wins — and `drum_tones` must not also be applied."""
+    alias_tones = {"base": "Alias Kit", "base_rig": "alias-kit"}
+    pak = _write_pak(
+        tmp_path,
+        {
+            "drum_tab": "drum_tab.json",
+            "drum_tones": ENTRY_TONES,
+            "arrangements": [
+                {"id": "lead", "name": "Lead", "file": "arrangements/lead.json"},
+                {"id": "drums", "name": "Drums", "type": "drums",
+                 "drum_tab": "drum_tab.json", "tones": alias_tones},
+            ],
+        },
+        files={"drum_tab.json": _tab("Drums")},
+    )
+    parts = _load(pak, tmp_path).drum_parts
+    assert len(parts) == 1
+    assert parts[0]["tones"] == alias_tones
+
+
+def test_drum_tones_does_not_leak_to_secondary_parts(tmp_path: Path):
+    """`drum_tones` is the PRIMARY's fallback only. A second drummer with no
+    binding of its own gets None — not the primary's kit."""
+    live_tones = {"base": "Live Kit", "base_rig": "live-kit"}
+    pak = _write_pak(
+        tmp_path,
+        {
+            "drum_tab": "drum_tab.json",
+            "drum_tones": ENTRY_TONES,
+            "arrangements": [
+                {"id": "lead", "name": "Lead", "file": "arrangements/lead.json"},
+                {"id": "drums-live", "name": "Drums (Live)", "type": "drums",
+                 "drum_tab": "drum_tab_live.json", "tones": live_tones},
+                {"id": "drums-prog", "name": "Drums (Prog)", "type": "drums",
+                 "drum_tab": "drum_tab_prog.json"},
+            ],
+        },
+        files={
+            "drum_tab.json": _tab("Drums"),
+            "drum_tab_live.json": _tab("Drums Live"),
+            "drum_tab_prog.json": _tab("Drums Prog"),
+        },
+    )
+    parts = {p["id"]: p for p in _load(pak, tmp_path).drum_parts}
+    assert parts["drums"]["tones"] == ENTRY_TONES        # primary, from drum_tones
+    assert parts["drums-live"]["tones"] == live_tones    # own entry
+    assert parts["drums-prog"]["tones"] is None          # no binding, no leak
+
+
+def test_drum_parts_carry_none_when_pack_binds_nothing(tmp_path: Path):
+    """A pack with drums and no sound binding at all still loads, with the key
+    present and None — consumers can read `part["tones"]` unconditionally."""
+    pak = _write_pak(
+        tmp_path,
+        {"drum_tab": "drum_tab.json"},
+        files={"drum_tab.json": _tab("Drums")},
+    )
+    parts = _load(pak, tmp_path).drum_parts
+    assert parts[0]["tones"] is None
+
+
+def test_malformed_drum_tones_is_ignored(tmp_path: Path):
+    pak = _write_pak(
+        tmp_path,
+        {"drum_tab": "drum_tab.json", "drum_tones": "not-a-dict"},
+        files={"drum_tab.json": _tab("Drums")},
+    )
+    assert _load(pak, tmp_path).drum_parts[0]["tones"] is None

tests/test_tones.py

@@ -6,16 +6,17 @@ from tones import sloppak_tone_changes
 # ── sloppak_tone_changes (highway payload builder) ───────────────────────────
 
 def test_sloppak_tone_changes_sorts_and_returns_base():
-    base, changes = sloppak_tone_changes({
+    base, base_rig, changes = sloppak_tone_changes({
         "base": "Clean",
         "changes": [{"t": 12.5, "name": "Drive"}, {"t": 3.0, "name": "Clean"}],
     })
     assert base == "Clean"
+    assert base_rig == ""
     assert changes == [{"t": 3.0, "name": "Clean"}, {"t": 12.5, "name": "Drive"}]
 
 
 def test_sloppak_tone_changes_skips_malformed_markers():
-    _, changes = sloppak_tone_changes({
+    _, _, changes = sloppak_tone_changes({
         "changes": [
             {"t": "nan", "name": "BadStr"},
             {"t": float("inf"), "name": "Inf"},
@@ -29,18 +30,66 @@ def test_sloppak_tone_changes_skips_malformed_markers():
 
 
 def test_sloppak_tone_changes_handles_none_and_bad_base():
-    assert sloppak_tone_changes(None) == ("", [])
-    base, changes = sloppak_tone_changes({"base": 123, "changes": []})
-    assert base == "" and changes == []
+    assert sloppak_tone_changes(None) == ("", "", [])
+    base, base_rig, changes = sloppak_tone_changes({"base": 123, "changes": []})
+    assert base == "" and base_rig == "" and changes == []
 
 
 def test_sloppak_tone_changes_non_dict_input():
     """A truthy non-dict payload must not crash."""
-    assert sloppak_tone_changes(["not", "a", "dict"]) == ("", [])
-    assert sloppak_tone_changes("nope") == ("", [])
+    assert sloppak_tone_changes(["not", "a", "dict"]) == ("", "", [])
+    assert sloppak_tone_changes("nope") == ("", "", [])
 
 
 def test_sloppak_tone_changes_non_list_changes():
     """A truthy non-list `changes` value must not raise on iteration."""
-    base, changes = sloppak_tone_changes({"base": "Clean", "changes": 1})
+    base, _, changes = sloppak_tone_changes({"base": "Clean", "changes": 1})
     assert base == "Clean" and changes == []
+
+
+# ── rig bindings (feedpak-spec 1.18.0 §6.9) ──────────────────────────────────
+
+def test_sloppak_tone_changes_carries_rig_bindings():
+    """`base_rig` and per-change `rig` reach the wire — the binding a chart
+    declares is what core must hand the consumer that voices the part."""
+    base, base_rig, changes = sloppak_tone_changes({
+        "base": "Clean Rhythm",
+        "base_rig": "clean-rhythm",
+        "changes": [
+            {"t": 12.5, "name": "Lead Drive", "rig": "lead-drive"},
+            {"t": 48.0, "name": "Clean Rhythm", "rig": "clean-rhythm"},
+        ],
+    })
+    assert base == "Clean Rhythm"
+    assert base_rig == "clean-rhythm"
+    assert changes == [
+        {"t": 12.5, "name": "Lead Drive", "rig": "lead-drive"},
+        {"t": 48.0, "name": "Clean Rhythm", "rig": "clean-rhythm"},
+    ]
+
+
+def test_sloppak_tone_changes_omits_unusable_rig_ids():
+    """A non-string or blank `rig` is dropped rather than forwarded, so a
+    consumer can treat presence of the key as "this change binds a rig"."""
+    _, base_rig, changes = sloppak_tone_changes({
+        "base_rig": "   ",
+        "changes": [
+            {"t": 1.0, "name": "A", "rig": 7},
+            {"t": 2.0, "name": "B", "rig": ""},
+            {"t": 3.0, "name": "C", "rig": None},
+            {"t": 4.0, "name": "D", "rig": "  padded-id  "},
+        ],
+    })
+    assert base_rig == ""
+    assert changes == [
+        {"t": 1.0, "name": "A"},
+        {"t": 2.0, "name": "B"},
+        {"t": 3.0, "name": "C"},
+        {"t": 4.0, "name": "D", "rig": "padded-id"},
+    ]
+
+
+def test_sloppak_tone_changes_non_string_base_rig():
+    """A non-string `base_rig` must not crash or leak a non-id onto the wire."""
+    _, base_rig, _ = sloppak_tone_changes({"base": "Clean", "base_rig": 42})
+    assert base_rig == ""