- Sequence mode: bars (2/4/6/8) with one chord per bar, chosen by
functional rules (I->IV/V/vi...), diatonic cycle, or random (no immediate
repeats); deterministic via melody seed. Chord symbols per bar in the
score model (chordSymbols) rendered above the staff via setSection.
- Rhythm: quarters or eighths (cycling up/down through the pattern).
- Single-chord mode unchanged (whole path, overflow bars if needed).
- Auto-start: 'Start on first note (no count-in)' — step pace begins the
run as soon as the mic detects the first note; no start press needed.
- 'New' button re-rolls the progression (new seed).
- Tests 174/174.
- music/arpeggioGenerator.ts: diatonic triads (I-vii*) built from the
selected key/mode via the shared degree spelling; patterns up / down /
up-down / 1-2-3-5; one or two octaves (cycle ends on the octave; two-
octave path continues from the turning root). Quarter-note rhythm with
final note extended to fill the bar; title is labeled 'Arpeggio -
<tonic> <degree> (pattern, coverage)'.
- Settings: PhraseMaterial 'arpeggio' + arpeggioDegree/Pattern/Coverage
(defaults I / up / one-octave).
- PhraseTrainer: material option 'Arpeggios (generated)' + Chord/Pattern/
Coverage/Meter selects; key/mode reuse the shared Target key controls.
- Tests: 9 arpeggio cases (170 total).
