Generation

README.md

@@ -105,11 +105,11 @@ Identical notation bodies share layout and body rasterization even when titles o
 
 The build-time pipeline is Soundslice/MuseScore -> `.xml` -> musical model and rhythm plans -> part generation -> JSON, engraved PNG pages, generated-tone audio, Pico title artwork, and a read-only catalog database. Sources in `data/songs/` retain the seven-section performance form. Four-digit numbered sources in `data/practice/` (currently `0001.xml` through `0366.xml`; `0000.xml` is also valid) produce one pass each of **acoustic accompaniment**, **electric melody**, and **vocal melody**. Both categories use the authored musical key, with no key variants or key-selection menu. Duplicate titles never merge exercises.
 
-Accompaniment uses deterministic four-bar phrase cycles: a two-bar motif repeats with a one-beat variation in the fourth bar when a suitable candidate exists. Acoustic has independent bass and upper-chord rhythms, including simultaneous attacks, sharing a playable grip. Bass alternates root/fifth unless an explicit bass or playability requires otherwise. Electric accompaniment responds more sparsely with stabs lasting at most a quarter note. Rhythm snippets supply attacks and rests; structured harmony supplies chord tones. N.C. and absent harmony remain silent. Solo slashes and the seven-section form retain their roles. Unsupported accompaniment meters and mid-measure meter changes fail explicitly.
+Accompaniment uses deterministic four-bar phrase cycles: a two-bar motif repeats with a one-beat variation in the fourth bar when a suitable candidate exists. Acoustic has independently planned bass and upper-chord rhythms, including simultaneous attacks, sharing a playable grip. They combine into one notated voice: sustaining notes use ties, simultaneous tones share a stem, and rests appear only when the entire part is silent. Bass alternates root/fifth unless an explicit bass or playability requires otherwise. Electric accompaniment responds more sparsely with stabs lasting at most a quarter note. Rhythm snippets supply attacks and rests; structured harmony supplies chord tones. N.C. and absent harmony remain silent. Solo slashes and the seven-section form retain their roles. Unsupported accompaniment meters and mid-measure meter changes fail explicitly.
 
 There are no musical genre presets, genre defaults, or genre metadata. Obsolete `vamp:style` hints are rejected; visual styles, fonts, colors, and barline notation remain supported. Phrase cycles are written into the generated score and played once in reading order.
 
-Guitar parts share a theory-based voicing and proximity search over standard tuning, frets 0-20, and a maximum four-fret span excluding open strings. Acoustic uses a bass on string 5 or 6 and two or three consecutive upper strings within 2-4, with zero or one unused string between them. Electric chords use strings 1-3 or 1-4 and may omit the root. Electric melody notes longer than a quarter note, including full tied runs, receive chords when playable; chord changes create fresh attacks even for short remaining fragments. Song electric melodies are raised one octave; practice and vocal registers stay unchanged. All parts still sound one octave below their generated notation, and explicit MusicXML transposition is honored once. Unplayable melody harmonizations remain single notes with a diagnostic; unplayable accompaniment fails generation.
+Guitar parts share a theory-based voicing and proximity search over standard tuning, frets 0-20, and a maximum four-fret span including open strings. Open strings can accompany frets 1-4, but not distant positions such as 11 or 12. Acoustic uses a bass on string 5 or 6 and two or three consecutive upper strings within 2-4, with zero or one unused string between them. Electric chords use strings 1-3 or 1-4 and may omit the root. Electric melody notes longer than a quarter note, including full tied runs, receive chords when playable; chord changes create fresh attacks even for short remaining fragments. Song electric melodies are raised one octave; practice and vocal registers stay unchanged. All parts still sound one octave below their generated notation, and explicit MusicXML transposition is honored once. Unplayable melody harmonizations remain single notes with a diagnostic; unplayable accompaniment fails generation.
 
 All parts use two music systems per page, with a single system only when the score ends on an odd system. 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.