Accidentals are authored explicitly per note per voice, with no shared carry-forward state — this makes the classic cross-voice accidental-ambiguity fault structurally impossible

Under traditional engraving, an accidental holds for the remainder of the bar for that voice/octave only — it does NOT apply to a different voice sharing the same stave, even at the identical pitch and bar. The classic engraving fault this convention guards against is a reader misreading a first voice's accidental as also applying to a second voice's identical-looking note.

A reader assuming voice 2's note is also sharped because voice 1's identical-letter note earlier in the bar carried a sharp, when voice 2's note was actually natural.

Gould, Behind Bars, and Ross, The Art of Music Engraving, both state accidentals are scoped per voice, not per staff.

This rule can be decided from pitches, durations and voices — no layout required. A validator can check it before anything is drawn.