Generation

README.md

@@ -111,11 +111,11 @@ Accompaniment uses deterministic four-bar phrase cycles: a two-bar motif repeats
 
 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 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. Electric melodies are raised one octave; 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 1-20, and a maximum four-fret span. Open strings are excluded from chords and single-note melodies. 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. Electric melodies are raised one octave; 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 or exact melody pitches fail 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.
+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.
 
-Electric melody prioritizes four-string chords, then melody on top, then root inclusion. Compact shapes, nearby positions, and fret comfort are preferred before optional chord tones; rootless voicings remain fallbacks, not equally desirable defaults. Electric accompaniment shares the fullness/root priorities. Acoustic instead favors simple grips, allowing bass plus two upper notes when that is easier than a four-note shape. Defining chord tones remain mandatory. All guitar placement uses a fret comfort threshold: frets 0-12 inclusive have no height penalty, and each fret above 12 adds two effort points based on the grip's highest fret. Frets 13-20 remain available; the soft penalty does not override musical priorities or force a less convenient move to a lower position. Exact melody pitches and rhythms remain unchanged.
+Electric melody prioritizes four-string chords, then melody on top. Every generated guitar chord requires the root, the fifth, or both; neither is preferred over the other. Acoustic favors simple grips, allowing bass plus two upper notes when that is easier than a four-note shape. Defining chord tones remain mandatory. Acoustic and electric chord scoring balances movement and span with a lower-position preference: the highest fret adds one effort point per fret, plus two more per fret above 12. Frets 13-20 remain available when movement savings justify them. Exact melody pitches and rhythms remain unchanged, and unharmonized melody placement retains its existing proximity scoring.
 
 Write all music in reading order: repeat bars, numbered endings, navigation jumps, and pass-specific ties are rejected. The seven-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 arrangement ending.