Background program: cut every 8 TRUE measures, on the beat

The video clip advance and the video<->demo alternation both counted chord-bar ticks, but a chord bar is state.chordEvery beats (default 8 = two 4/4 measures) — so "8 bars" was really 16 measures.

▶ Play it: Mercury Interrogation — where the harmony organ has the least anywhere to hide https://stellate.app/?genre=bebop&seed=2155&path=694.13834,713.13867,675.13867&xdur=13.122

501d053 https://github.com/aboard-io/stellate/commit/501d0533c1f310e0862a10aef9d463479c8a3c64