[snakajima]

Sheet music for music education. An LLM writes a short piece and shows it to the user either as a waveform or as sheet music. It can also have the piece start playing right away and be told when the user has heard it to the end.

Score format (sound unchanged)

• New optional top-level fields: meter ("3/4", "6/8"), key ("F", "Am") and pickup (beats before the first full bar).
• New optional track fields: clef (treble/bass) and notation: false.
• None of these affect rendering, and every existing golden hash still holds.

Library

• src/notation.ts turns a score into measures, staves and written note values. It handles ties, dots, triplets in quarter-note beats, accidentals, lyrics with hyphens and extenders, chord symbols, and a grand staff for piano.
• When a note has to be rounded onto the beat grid or shortened, it produces a warning for the LLM.
• src/musicxml.ts writes MusicXML 4.0 (partwise).
• checkScore adds notation warnings when the score sets meter, key or pickup, or when it is called with view: "notation".
• New renderScore options: view ("waveform" | "notation"), autoplay and notifyWhenDone. They are stored in the result's presentation.
• If a score itself contains these options, the error says they belong in the call, not in the score.
• When there is an output directory (the MCP case), <stem>.musicxml is written next to the audio.
• CLI: jinglescript notation <score> -o x.musicxml and check --notation.
• The guide has a new section, "Sheet music". README, schema, skill and plugin definition are regenerated.

GUI plugin

• New dependency: opensheetmusicdisplay (BSD-3-Clause; Verovio was ruled out as LGPL). It is external in the build and lazy-loaded only for the sheet-music view.
• Waveform / Sheet music toggle, a cursor that follows playback, a seek bar, and a MusicXML download.
• Hosts mount and remount every card in a chat. So a card autoplays only if it was rendered in the last 2 minutes, and only once. The finish message to the LLM (sendTextMessage) is sent once, on ended.
• Both facts are saved in the result's viewState through onUpdateResult.
• The plugin's instructions to the LLM vary with the chosen presentation.

Examples and eval

• Five new learn-* examples: C major scale, rhythms, Twinkle (grand staff), Happy Birthday (pickup, 3/4) and Row Your Boat (6/8). Each has an audio golden snapshot and a MusicXML snapshot.
• eval/requests-notation.json has 8 requests in English and Japanese. The eval/check.ts notation spec checks meter, key, pickup, harmonies and that there are no warnings.
• Default model: 8/8 on the first try.
• Haiku: 0/8 at first, because it put view into the score. After the guide fix and the new error hint, 8/8.

Verification

• yarn format, lint and typecheck pass.
• Root tests: 706 passed, 102 skipped. smoke.sh passes.
• Plugin: typecheck, 196 tests, build and playground build pass.
• Headless Chrome, on the playground and the demo:
  • All five examples draw correctly.
  • The cursor moves during playback.
  • The finish message is sent once, and not again on a replay.
• Not verified: autoplay without a click. Headless Chrome blocks it, and the "Press play to listen" fallback was shown instead.
• Not done: listening checks on the rendered examples. Audio is unchanged for existing scores.

Codex review (local, codex review --base origin/main)

Twelve rounds raised one or two P2 findings each. All were fixed with a test that fails without the fix. The thirteenth round found nothing.

• Sheet music that no longer matches the audio, with no warning. Each of these now gives a warning with the note's path:
  • an off-grid len
  • straight notes mixed with triplets inside one quarter
  • triplets in 6/8 or 3/8
  • notes that start together with different lens
  • any pickup that gets rounded
• Bars whose durations don't add up to their length (pickups of triplet length, a note rounded away, a 0.25 pickup next to triplets):
  • A test now writes 144 generated rhythms over 8 meters and 6 pickups and checks every bar.
  • A throwaway fuzz of 20 000 scores found 1 188 broken bars before the last fix and none after.
• Smaller fixes:
  • Triplets now also work in 2/2.
  • A note tied over a bar line no longer hides a later note's accidental.
  • A sound effect that takes a pitch (laser) stays off the sheet music.
  • Humanize can no longer swap lyric syllables.
  • A repeated note warns once.
• Player view:
  • A draw still loading is cancelled on unmount.
  • A player reused for another result starts over with that result's view and memory. Checked in the playground: before the fix, the second render kept the first one's view.
• The 16 scores from the earlier eval runs still give no notation warnings.

🤖 Generated with Claude Code

work in jinglescript

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	opensheetmusicdisplay@​2.2.1

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