Spread k hits as evenly as possible over n steps and you get E(k,n) — the pattern behind a startling share of the world's rhythms: the tresillo E(3,8), the cinquillo E(5,8), the 12/8 bell. Four drum lanes each run their own E(k,n) on the General MIDI drum map; give them different lengths and they loop against each other in polymeter. Rotate picks which hit lands on the downbeat (accented). Export drops a .mid clip on the GM drum channel, same as the Drum Machine's.