stack(
  n("[60 50 55 67]/2").color("yellow"),
  n("[42 ~]*2").color("blue"),
  n("[~ ~ 58 ~]").color("red"),
  s("[~ ~ <hh [bd,tb]> ~]").color("orange"),
  n("[[32,34] [40,42]]").color("purple")
).fast(6.9/1.2).pianoroll()