Comping

README.md

@@ -102,7 +102,7 @@ Six roles generate independently: acoustic accompaniment/solo; electric accompan
 
 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. 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.
+Accompaniment uses independently authored two-bar jazz pattern families: Charleston and shifted Charleston, forward-motion syncopation, anticipated heavy beats, syncopated riffs, quarters, dotted spacing, shifting motifs, call-response and anticipated beat four. Acoustic distributes a single figure between bass and upper chord, normally 1–3 total attacks per full bar, without mandatory beat-one bass. Separate attacks are quarters/eighths and never overlap; a combined bass-plus-upper chord is allowed only when both attack and sustain together for more than one beat. Electric has distinct patterns with normally 0–2 attacks per bar, stabs, sustained chords and space. The source melody and harmonic rhythm guide complete-pattern selection. Half-beat upper/electric anticipations may establish the next written chord; bass stays on current harmony. Explicit cross-bar holds use ties, never automatic merging of repeated attacks. Canonical patterns repeat at corresponding form positions with documented harmonic/pickup exceptions, and changing only tempo leaves the music unchanged.
 
 **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.
 
@@ -134,7 +134,7 @@ Add a source and its authored solo, then retrain the pooled model, without chang
 
 To retrain existing pairs, run `./modulus.py python -m generator.train`; add `--leave-one-song-out` for held-out likelihood diagnostics. Training writes `data/models/solo.json` and `build/training/report.json`. Ordinary builds use registered authored music or the saved model and never retrain automatically. Exact registered playback verifies authored reuse; it does not demonstrate model memorization or musical quality on unfamiliar songs. [Training and playback details](TECHNICAL_GUIDE.md#authored-repertoire-and-learned-solos) cover pairing, timing, pitch convention, data migration, and limitations.
 
-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.
+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 main performance sections plus the held Ending 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.
 
 All generated monophonic guitar material uses frets 1–12 without open strings. Chords use two span tiers: **one to three consecutive fret positions share the primary tier; exactly four positions are a fallback** (e.g. 7–9 is primary, 7–10 is fallback). Five or more positions are forbidden. Selection minimizes fallback use before family, melody-string, movement or register preferences. A chord can extend to fret 20 while retaining at least one sounding anchor on frets 1–12 throughout its duration. Acoustic bass remains within frets 1–12 and upper chords need their own anchor when played separately. Some chord/key combinations still have no legal inversion; 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.
 
@@ -142,17 +142,17 @@ There are no genre presets or runtime composition. The complete arranged score i
 
 All parts use two music systems per page, with a single system only when the score ends on an odd system. Lines break only between measures and share consistent staff/TAB widths. A measure that cannot fit at readable spacing fails with a diagnostic instead of being split. Tall notation is scaled uniformly to fit the two rows; guitar notation and TAB stay together and aligned. TAB displays frets and ties without duplicate rests; standard notation retains the complete rhythm. The generated `.pages/*.png` files are the same page images displayed by the product.
 
-Write all music in reading order: repeat bars, numbered endings, navigation jumps, and pass-specific ties are rejected. The six-section performance arrangements remain fully written out. Chord labels use `M`, `m`, `aug`, `dim`, `sus`, and `mM7`, including explicit major triads such as `CM`. Recognized Soundslice text-only harmonies are normalized into structured chords; parenthesized chords mark optional turnarounds omitted from the final vocal pass.
+Write all music in reading order: repeat bars, numbered endings, navigation jumps, and pass-specific ties are rejected. The performance arrangements, including the held Ending, remain fully written out. Chord labels use `M`, `m`, `aug`, `dim`, `sus`, and `mM7`, including explicit major triads such as `CM`. Recognized Soundslice text-only harmonies are normalized into structured chords; parenthesized chords mark optional turnarounds omitted from the final vocal pass.
 
 Settings provides independent **Metronome** and **Backing** toggles, both off by default, plus **Tempo**. Song -> Part -> Score navigation stays the same. With both toggles off, pages turn manually. With either enabled, opening a part starts a one-bar count-in and an automatic performance; tap/double-tap page commands are ignored, and hold exits to the part menu. Natural completion also returns there.
 
-A performance is an eight-bar intro followed by five complete passes: Vocal Melody, Guitar Melody, Acoustic Solo, Electric Solo, and Vocal Melody. There is no separate Ending section. The current 32-bar songs contain 168 numbered bars. Optional turnaround chords are omitted from the final vocal pass.
+A performance is an eight-bar intro followed by five complete passes: Vocal Melody, Guitar Melody, Acoustic Solo, Electric Solo, and Vocal Melody. A final Ending section adds one guitar chord attack sustained across three full measures, with vocal rests. The current 32-bar songs contain 171 numbered bars. The ending holds the final performed harmony (GM6 for All of Me, Dm for Autumn Leaves). Optional turnaround chords are omitted from the final vocal pass.
 
 Audio comes exclusively from supplied WAV files: `package/assets/sounds/beat1.wav` accents each measure's first beat, and `beat2.wav` plays its other beats. Backing tracks belong in `package/assets/backing/<song_id>_<bpm>.wav`, for example `all_of_me_120.wav`. The normalized song ID comes from the source filename. Files are copied unchanged; the app never synthesizes notes or stretches recordings.
 
 Tempo choices are 60, 70, 80, 90, 100, 110, and 120 BPM. With Backing on, choices are the tempos available for every catalog song; currently that is 120 BPM. Enabling Backing selects the closest available tempo, preferring the slower choice on a tie. If no tempo is shared, Backing is unavailable. Add recordings at the other tempos and rebuild to enable them.
 
-Backing recordings include one bar of count-in, the complete score, and the held ending with decay. The recorded count-in plays alone. When both toggles are on, metronome clicks start at the score and stop at its end, leaving the last three held bars and decay unclicked. Metronome-only mode supplies its own count-in and stops at score end. Pages follow the rendered audio clock, using each engraved page's actual measure range; the final page stays visible through the backing tail.
+Backing recordings include one bar of count-in, the complete arrangement including its three-bar held ending, and decay. The existing WAVs are copied unchanged. The recorded count-in plays alone. Metronome clicks stop at the start of the written Ending section; those three measures and the decay remain unclicked. Metronome-only mode supplies its own count-in, waits silently through the ending, and then stops. Pages follow the rendered audio clock through all 171 measures; the final page stays visible through the recording decay.
 
 Code style is managed by Modulus, using compact two-space formatting. Python imports modules by their full names and qualifies imported symbols; only `from __future__ import annotations` is exempt, and imports have no aliases. Run `./modulus.py format` to format C++ and Python, or `./modulus.py format --check` to check formatting and prohibited aliases. The project-local Neovim integration routes Conform formatting through the same container tools, including format on save and existing LazyVim toggles. Run configure first when the image or exported tooling needs updating. Use `tooling.editor.clang_format` for C++ overrides and `tooling.format.exclude` for project-relative exclusion globs; do not edit generated `.clang-format` files.