Beam stroke count must match each note's duration (single beam = eighth, double = sixteenth, triple = 32nd)

The number of beam strokes connecting a group of notes must correspond exactly to each note's written duration — a mismatch (e.g., a sixteenth note drawn with only one beam stroke) misrepresents the rhythm.

A dotted-eighth-to-sixteenth pair renders with the SAME beam-stroke count on both notes (e.g., both single-beamed) instead of the dotted eighth showing one full stroke plus a partial second stroke and the sixteenth showing two full strokes.

Universal notation convention (Gould, Read, Ross, SMuFL beam-stroke glyph conventions all agree).

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