Rhythm Comping Pairs

TECHNICAL_GUIDE.md

@@ -133,7 +133,7 @@ Silent spans retain the preceding hand position. A continuous accompaniment repe
 
 `comping_rhythm.py` selects recurring source-only figures from version 6 of `composition/accompaniment.json`. The normal acoustic cycle has two two-bar slots; electric has four. Each template and anticipation mode is evaluated at every occurrence of its slot before retrieval limits apply. Up to eight diverse candidates per slot enter bounded complete-cycle comparison. Distinct slots differ in attack/duration relationships, not just IDs, bass/upper assignments or anticipation flags. Repetition is not penalized. The source melody and harmonic rhythm affect selection; title, iteration, generated solo and tempo do not. `groove_cycles` reports slot identities, anticipation modes, aggregate cost, compared cycles and any reduction caused by vocabulary or form length.
 
-Meter-specific full patterns declare `meter` and, for 5/4, `grouping: [3, 2]` or `[2, 3]`; `meter: partial` marks the bounded one-bar pickup vocabulary. The loader checks nominal lengths, grouping, quarter/eighth arithmetic, lane overlap and distinct acoustic/electric onset patterns. Each role has 24 distinct attack/duration figures per selectable pool: 4/4 (11 families), 3/4 (12 families), and each 5/4 grouping (12 families). The 4/4 pool removes one duplicate acoustic figure, develops another previously duplicated answer, and adds three electric variants. Patterns are independently authored from general principles, with research URLs and provenance in the resource, rather than transcriptions. The counts describe available choices, not required musical activity.
+Meter-specific full patterns declare `meter` and, for 5/4, `grouping: [3, 2]` or `[2, 3]`; `meter: partial` marks the bounded one-bar pickup vocabulary. The loader checks nominal lengths, grouping, quarter/eighth arithmetic, electric lane overlap and distinct acoustic/electric onset patterns. Acoustic lane overlap is checked after automatic assignment. Each role has 24 distinct attack/duration figures per selectable pool: 4/4 (11 families), 3/4 (12 families), and each 5/4 grouping (12 families). The 4/4 pool removes one duplicate acoustic figure, develops another previously duplicated answer, and adds three electric variants. Patterns are independently authored from general principles, with research URLs and provenance in the resource, rather than transcriptions. The counts describe available choices, not required musical activity.
 
 `grouping_for` is a pure source-only decision. It honors written 3+2 or 2+3, otherwise compares actual chord changes at the secondary boundary, then melody entrances following at least an eighth-note rest, then other melody attacks; equal evidence defaults to 3+2. An unchanged chord marking is not a change. The selection stays fixed through a continuous meter section, and each role derives it independently from the same source. Fills cannot borrow another grouping. No accents or playback swing changes are inferred. `groove_cycles` additionally reports grouping, its evidence and the eligible pattern count. Equal-duration compound meters (such as 6/8) do not borrow the 3/4 vocabulary; unsupported comping meters fail explicitly.
 
@@ -143,16 +143,20 @@ The cycle begins at the first full source-body measure. A partial-form entry fir
 
 Fills replace only a two-bar figure's ending bar, using a same-family variation that improves the existing source-fit objective. Eligible boundaries are source section endings, form endings, or a melody breath of at least one quarter-note beat at the block end. Carried events from the opening bar are protected. The largest improvements are retained with an eight-measure minimum separation around the whole cyclic form, equally for both roles; no fill quota applies. Fills do not change cycle phase and recur at identical source positions. Reports record the base slot, selected fill, source index and reason.
 
-Normal acoustic patterns use 1–3 attack positions per full bar. Separate bass and upper events last quarters/eighths and may overlap; paired attacks can be short or sustained. Events cannot overlap within the same lane. First attacks of new harmonic spans include bass (`first_attack: bass_per_harmony`), including mid-bar changes; continued harmony does not reset at barlines or computational boundaries. Fitting can pair bass with an upper attack without changing its onset, with independent releases where necessary. A paired attack counts once in rhythm evaluation. The completed validator follows sounding tie chains; placement validates all simultaneously sounding strings, fret spans and anchors. The two lanes are merged into one notated part with tied fragments preserving their true durations.
+Normal acoustic patterns use 1–3 attack positions per full bar. Their event layer is `acoustic`; the instrument's versioned `attack_assignment` policy is `combined_except_eighth_pairs`. Authored bass/upper decisions are replaced by chronological assignment across the complete canonical source form: ordinary attacks are combined, while adjacent half-beat-separated attacks in the same effective harmony become bass then upper. Pairs do not overlap; an odd leftover attack is combined. Bar and two-bar pattern boundaries do not reset pairing. Source-defined entries, handoffs and chorus boundaries do; the same boundary set applies at repeated form positions. Chord changes break pairs, but repeated identical chord labels do not. An anticipation uses its upcoming harmonic region for this decision. First attacks of new harmonic spans still include bass (`first_attack: bass_per_harmony`).
 
-Electric normally uses 0–2 attack positions per bar, with stabs, sustains and space. Direct events release at changed harmony. An eligible upper/electric template can anticipate a chord by half a beat when it continues into that chord; the grip comes from the upcoming harmony and releases by its following change. Acoustic anticipations also include bass on the new chord's first attack. Conflicting lane overlaps reject the candidate. Missing harmony remains silent. Protected participation limits retain the chosen figure, shortening only its affected releases and recording exceptions. Cross-bar sounding notes become ties, never automatic merging of repeated attacks.
+Quarter/eighth articulations and explicitly authored sustains retain their duration unless a chord boundary, handoff or fresh attack on the same strings requires release. Bass may ring beneath a later upper attack. Shortening that would strand an anticipation first rebinds it to current harmony and recomputes assignment. Complete-form assignment happens before grip placement and notation splitting, and is re-evaluated for source-harmony variants. Concrete block caches include their assigned event signature: a neighboring chord change can break a pair even when this block's own harmony is unchanged. The renderer verifies actual sounding lane events against the selected assignment. The completed validator follows sounding tie chains; placement validates all simultaneously sounding strings, fret spans and anchors. The two lanes are merged into one notated part with tied fragments preserving their true durations. The three-bar closing sustain remains combined.
+
+Electric normally uses 0–2 attack positions per bar, with stabs, sustains and space. Direct events release at changed harmony. An eligible acoustic/electric template can anticipate a chord by half a beat when it continues into that chord; the grip comes from the upcoming harmony and releases by its following change. Acoustic anticipations also include bass on the new chord's first attack. Missing harmony remains silent. Protected participation limits retain the chosen figure, shortening only its affected releases and recording exceptions. Cross-bar sounding notes become ties, never automatic merging of repeated attacks.
 
 All six production roles receive reuse audits. Musical comparisons include rests, pitch durations, ties and TAB while ignoring regenerated event IDs and global measure numbers. Source-defined pickup/participation changes and effective final-turnaround harmony are reported separately. The final three-bar hold remains instrumental.
 
-Named activity, melody-support, harmonic-support and articulation contributions evaluate complete figures. Cycle selection aggregates them over all occurrences, retaining family diversity before the final bounded comparison. `groove_cycles.cost` is the selected base cycle's aggregate cost before optional fills. Reports identify the base slot, realized pattern, projected events, continuations, anticipation target times and source-context exceptions. Tempo affects metadata/cache identity but never musical choice.
+Named activity, melody-support, harmonic-support and articulation contributions evaluate complete figures. Cycle selection aggregates them over all occurrences, retaining family diversity before the final bounded comparison. For electric, `groove_cycles.cost` is the selected base cycle's aggregate cost before optional fills. Acoustic reports preserve this as `retrieval_cost` and report `cost` for the final assigned source-form events, including selected fills and cross-block pairing. Reports identify the base slot, realized pattern, projected events, continuations, anticipation target times and source-context exceptions. Tempo affects metadata/cache identity but never musical choice. The acoustic assignment policy and data migrate independently; the electric choice domain and other roles' musical seeds are unchanged.
 
 Acoustic events use temporary bass/upper notation lanes for projection; then `acoustic.combine` converts their sounding intervals to one rhythmic voice before assembly. It splits notes at attack/release boundaries and ties only continuing pitches; repeated attacks stay separate. Staff and TAB share the result, with no competing rests or opposing layer stems. This preserves exact sounding durations instead of truncating overlaps. The older truncating `prepare` helper serves only the noncanonical legacy/test path. The product build audits canonical accompaniment reuse across arrangement iterations, allowing only source-derived changes in harmony, pickups and role handoffs. The `.roles` sidecars report pattern IDs, exact projected layer events, continuations, anticipation targets and exceptions. Their `selection_cost` records the complete figure’s local contributions, repeated on each projected bar for context; the cycle selector aggregates these by the number of measures in each occurrence, without an anti-repetition transition cost. Accompaniment dependency keys contain only that instrument's policy; electric melody consumes the shared electric voicing families. Solos retain their existing learned source-melody/harmony conditioning and registered exact performances.
 
+Acoustic pair-assignment verification on October 7, 2026: the full containerized `unittest discover -s tests -p 'test_*.py'` passed 447 tests. After adding the explicit cross-bar meter case and retaining the existing long-sustain boundary semantics, the final targeted run (`tests.test_acoustic_pairs tests.test_comping_rhythm tests.test_comping_cycles tests.test_comping_meters tests.test_arrangement_ending tests.test_chord_families.CombinedAcoustic`) passed 63 tests. The first full run exposed a broken-tie check that had depended on rejecting a long separate event; explicit reciprocal-link, timing and pitch/TAB checks now reject it directly. A host-only targeted command could not import Modulus's build dependencies; the configured-container rerun passed. Native and ARM product builds passed asset checks, with 394 identical JSON/PNG artifacts. Both acoustic score/TAB pages were visually inspected. All ten other-role documents exactly match the saved pre-change baseline. The acoustic source-form reports show 64 combined attacks for All of Me, and 48 combined plus 16 bass/upper pairs for Autumn Leaves; these are observations, not quotas. No audio audition was performed. Comparison copies remain outside the repository under `/tmp/`.
+
 Monophonic solos use strings 1–6 and frets 1–12, with no open strings or acoustic/electric string restrictions. Placement compares complete paths through legal positions, accounting for hand-region changes, travel time and string crossings. Ties retain their position. Chord placement retains its separate policy: frets 1–20, a sounding anchor on frets 1–12, primary spans of up to three consecutive positions and fallback spans of exactly four. The span is inclusive: 7–9 is three positions, 7–10 is four. Five positions are always invalid. The anchor must remain sounding, including after shorter notes release. Acoustic accompaniment additionally keeps its bass within frets 1–12 and requires an independent anchor in its upper three-note cluster, preserving the option of separate bass/upper attacks. These costs approximate physical feasibility; they do not assign fingers or guarantee comfortable playing.
 
 Both accompaniment roles add `register_weight * abs(mean sounding MIDI - center)` and `high_position_weight * max(0, mean fret - comfortable_max_fret)` to their existing grip effort and movement tier, once per active harmonic span. The three role policies (`acoustic_accompaniment`, `electric_accompaniment`, `electric_melody`) use weights 1 and 1 and threshold 9; their register centers are 53, 60 and 60 respectively. All arithmetic is rational. Electric melody adds the same costs only to harmonized attacks, below compact-span, melody-string, foreground, chord-size and family priorities. Exact melody pitches are never transposed to meet the register center; monophonic placement is unchanged. Scoring and scored-pruning caches explicitly include the normalized preference tuple. Tied continuations incur no second chord cost. Existing travel costs and source-form joins remain in place; high positions can still win when avoiding a costly shift. The ending uses its own accompaniment role's local cost and incoming grip.