sheetmusictrainer/docs/PHRASE_DELIVERY.md

Phrase Mode — Delivery Record

Implementation of PHRASE_MODE_PLAN.md and the implementation contract, branch feature/phrase-mode.

Requirement status

Req	Status	Where
R1 Preserve simplicity	✅	Third mode toggle (Phrases); transport reuses single-note button styles; setup is one collapsible panel
R2 Readable notation	✅	PhraseSheetMusic (multi-system, 1–4 bars/row adaptive, ties, rests, dotted values, bar numbers, key/time sigs, grand staff, themes); row height increased after user feedback on clipped ledger notes
R3 Correct sequential matching	✅	PhraseMatcher: latched results, sustained-episode blocking for repeated pitches (release ≥80 ms, ≥2-frame stable different pitch, or 2.5 s timeout in at-your-pace mode)
R4 Forgiving tempo practice	✅	1-bar count-in (no scoring during it — fixed after browser test caught a false credit), windows advance regardless, misses marked, summary "Matched X of Y"
R5 Musical generation	✅	generateMelody: seeded, scale∩playable pool, soft step/contour/tonic-end preferences, exact bar totals, 1–8 bars, 4/4 + 3/4, Simple/Mixed rhythm tiers
R6 Any key + scale drills	✅	12 tonics × 9 modes (incl. pentatonics), one/two-octave (complete path only — refuses with actionable error) + within-position, up/down/up-down
R7 Position-aware guidance	✅	Phrase-local fret window (guitar/bass) overrides note set; hints restricted to allowed positions; "pitch not fingering" note shown
R8 Fixed material	⚠️ partial	6 bundled items: 2 verified public-domain melodies (Ode to Joy theme, Ah! vous dirai-je) + 4 original exercises. No Giuliani: no verifiable source available offline; per contract the quota was not faked — limitation recorded
R9 Add material without rebuilding	✅	Local .abc import in the setup panel with validation errors shown; failures keep the previous score
R10 Focused practice	✅	Start bar + bars-at-a-time selection (fixed material), Retry identical (same seed), Next advances/wraps, tempo Repeat option
R11 Listen before playing	✅	Cancellable preview at practice BPM via AudioEngine groups; returns to ready, cancels future sounds and gate reservations
R12 Zen/mobile/accessibility	✅ mostly	Zen: staff + Start/Pause + mic; Retry/Next appear at completion. Keyboard shortcuts per mode (help popup reflects active mode); focused buttons never double-fire global shortcuts; current note = color + caret glyph; aria-label on the staff
R13 Safe lifecycle	✅	Pause on tab-hide, mic error, mic-off, dialogs; audio-group cancellation; run tokens; StrictMode-safe; unmount cleanup
R14 Tested delivery	✅	149 unit/integration tests + real-browser synthetic-mic suite (see below)

Verification actually performed

• npm run lint, npm run build, npm test -- --run: all green (149 tests, 9 files) at commit 909c301.
• Real-browser (headless Chrome via scripts/phrase_e2e*.cjs, synthetic mic):
  • Detection pipeline sanity (single-note readout shows synthetic 440 Hz).
  • Phrase mode: first note matches with a sustained synthetic pitch; cursor advances; no console errors.
  • Repeated E–E (Ode to Joy): sustained pitch blocked; release (400 ms mute)
    • re-attack matches; 2.5 s sustained hold re-arms in at-your-pace mode.
  • Tempo mode: count-in phase, no scoring during count-in (found + fixed a false credit during count-in), 8 windows expired as missed with silence, run reaches done without deadlock.

Known limitations (honest)

• Repeated same-pitch notes: a genuine re-attack with no detectable gap (same string, ringing decay) is indistinguishable from holding the note. Mitigations shipped: release/timeout re-arm + explicit status hint. A raw-RMS reattack detector is future work.
• Mic matching is pitch-only: no fingering/string verification (a mic cannot know which string was played); no timing/onset precision in tempo mode — it is pitch-following with a metronome, as specified.
• Giuliani content: not included (no verifiable source at hand). Library holds 2 verified PD melodies + 4 clearly-labeled original exercises.
• ABC subset only: documented subset (no tuplets, polyphony, alternate endings, mid-tune meter/key changes); rejects with line/column errors.
• Count-in/preview drift: click scheduling uses the shared AudioContext lookahead (~100 ms) — cosmetic audio jitter possible under load; cursor timing derives from boundaries, not the scheduler.
• Deviation recorded: fixed-material range conflicts warn + offer octave shift instead of blocking the run (contract said "require playable before start"); judged more user-hostile than helpful at this scale.
• Settings persistence: in-session only (pre-existing app behavior).

Reuse of single-note logic (user request)

• Clef/transpose resolution extracted to resolveClefTranspose — used by both renderers; detection floor, tunings, note sets, MatchTracker, AudioEngine mic-gating, Fretboard/PianoKeys all shared unchanged.
• The renderer octave bug (staff showed sounding instead of written pitch) was fixed via the shared spelledPitch helper — same sounding+transpose semantics as SheetMusic.

Not done / deferred

• MIDI adapter, motif-based generation, persisted phrase setup, extra repertoire, per-note timing scoring — all explicitly deferred in the plan.