- STYLE_user renamed to STYLE_H1K0 in VOCAB (author's personal tag)
- Style field now accepts any [A-Za-z][A-Za-z0-9_]* identifier in .chord files
- Unknown styles fall back to STYLE_other at tokenization time with a log warning
- Test fixtures updated to style: other; drop closed _VALID_STYLES frozenset
- Spec bumped to v2.1: documents open style field, fallback behaviour, and §5.7
guide on registering a new style token
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
chord_file_to_midi() parses the period in the user's original key (no
transposition), accumulates held-chord segments, then writes two pretty_midi
tracks: chords with root anchored at octave 4 (MIDI 60–71 + intervals) and
bass at octave 2 (MIDI 36–47). Extension notes are added as a fifth voice
at their standard interval above the root. Tempo is parameterised; the CLI
wrapper (python -m src.midi_export) supports --tempo BPM.
10 tests cover: file creation, parseability, instrument count and names,
chord/bass note counts for a 4-chord C-major fixture (14 chord + 4 bass),
octave placement assertions, and tempo affecting total duration.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
H1K0