Chord Families

README.md

@@ -100,9 +100,9 @@ Uncompressed MusicXML 3.1/4.0 source scores exported from Soundslice or MuseScor
 
 Six roles generate independently: acoustic accompaniment/solo; electric accompaniment/melody/solo; vocal melody. A process pool and per-role caches support parallel and incremental builds. Each role uses the source and its own inputs without reading another generated role. Canonical accompaniment repeats at corresponding source-form positions and does not react to generated solos. Vocal melody preserves the authored notes and lyrics. Electric melody preserves source pitches and harmonizes eligible sustained notes, reattacking them at chord changes.
 
-Electric accompaniment uses the electric melody's three/four-note voicing families on strings 1–4. Acoustic accompaniment uses one bass note on string 5 or 6 and three upper notes on strings 2, 3 and 4. Its bass can be the root or written fifth, or any triad member for plain major/minor chords; an explicit slash bass or inversion takes priority. Each instrument selects a connected voicing path across the source form to reduce hand movement, then reuses it through the arrangement.
+Electric accompaniment and electric melody share compact chord families on strings 1–4. Melody harmonization adapts these to keep the original melody on the lowest-numbered feasible string, preferring it above the added chord tones. The separate Electric Solo stays monophonic. Acoustic accompaniment uses one bass note on string 5 or 6 and three upper notes on strings 2, 3 and 4. Transposable degree families cover triads, sevenths/sixths, suspensions, diminished/augmented and extended/altered chords, with root/fifth bass alternatives on both bass strings. Plain major/minor chords also allow third basses; explicit slash basses and inversions take priority. Unplayable variants are discarded. Each instrument selects a connected voicing path across the source form to reduce hand movement, then reuses it through the arrangement.
 
-Accompaniment rhythm is light at every tempo: normally 0–2 electric chord attacks, 1–2 acoustic bass attacks, and 1–3 acoustic upper-chord attacks per full measure. Bass attacks beat one wherever harmony is available. Stabs, sustains and space follow the original melody and harmonic rhythm. Separate acoustic voices allow bass and upper notes to overlap; their combined attacks are evaluated for crowding. An extra attack is permitted only for harmonic changes and reported. Compatible holds can tie across barlines. The selected accompaniment repeats at corresponding form positions, with source-defined pickup/handoff exceptions, and does not change when only tempo changes.
+Accompaniment rhythm is light at every tempo: normally 0–2 electric chord attacks, 1–2 acoustic bass attacks, and 1–3 acoustic upper-chord attacks per full measure. Bass attacks beat one wherever harmony is available. Acoustic attacks last a quarter or eighth note; electric chords mix stabs, sustains and space. Both consider the original melody and harmonic rhythm. Acoustic bass and upper notes appear in one rhythmic voice on the same staff/TAB, with ties preserving any overlapping durations. Combined attacks are evaluated for crowding. An extra attack is permitted only for harmonic changes and reported. Compatible electric holds can tie across barlines. The selected accompaniment repeats at corresponding form positions, with source-defined pickup/handoff exceptions, and does not change when only tempo changes.
 
 **Registered Solo 1 is notated exactly in the acoustic part and Solo 2 exactly in the electric part.** Unregistered song/slot pairs use deterministic prediction from one pooled statistical model trained on both slots. There is no learned acoustic/electric style distinction. Prediction uses up to four recent pitch/rhythm events, source-melody features, harmony, and metrical position; it does not plan complete themes or guarantee long-range phrase development. The current corpus is four authored solos from Autumn Leaves and All of Me.
 
@@ -138,7 +138,7 @@ To retrain existing pairs, run `./modulus.py python -m generator.train`; add `--
 
 The build-time pipeline is MusicXML -> source analysis -> independent roles -> assembled parts -> semantic JSON, supplied recordings, engraved PNG pages, Pico title artwork, and a read-only catalog database. Each source produces the six-section performance form as Acoustic, Electric, and Vocal parts in its authored key, without key variants or a key-selection menu. Performance measure numbers run continuously across the complete arrangement, starting at 1 in the lead-in; they do not restart with a new section or chorus. Pickups occupy the preceding measure. Standalone comparison XMLs use local measure numbers and retain the original arrangement numbers in `manifest.solo`.
 
-All generated monophonic guitar material uses frets 1–12 without open strings. Accompaniment uses all legal compact positions; a chord can extend to fret 20 while retaining at least one sounding anchor at fret 12 or below and the existing three-fret span restriction. Electric source-melody harmonization retains its separate placement and chord-change reattack policy. Import preserves exact source pitches and ties; unplayable or unsupported input fails explicitly rather than being silently octave-folded.
+All generated monophonic guitar material uses frets 1–12 without open strings. Accompaniment uses all legal compact positions; a chord can extend to fret 20 while retaining at least one sounding anchor at fret 12 or below, within three consecutive fret positions (e.g. 7–9, not 7–10). Acoustic bass remains within frets 1–12 and upper chords need their own anchor. Some chord/key combinations have no legal inversion under these combined constraints; generation reports them instead of removing required tones. Electric source-melody harmonization retains its chord-change reattack policy. Import preserves exact source pitches and ties; unplayable or unsupported input fails explicitly rather than being silently octave-folded.
 
 There are no genre presets or runtime composition. The complete arranged score is played in reading order. The source-defined form and continuous whole-arrangement measure numbering remain unchanged.