Home : Tune Toys : Expresso 
  Expresso takes a simple musical expression (literally "X") and mutates it. In each generation, transformations are applied to components of the expression. This is a fractal technique known as an L-system. The more generations there are, the larger and more complex the expression gets (and the longer it can take to compute). The output varies wildly, from boring to fascinating. Press "Mutate" a few times till you get something that looks interesting, then click on the image to play it. See Composer's Quarry for examples of output.

Transformations:
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After 16 generations the expression "X" became this:
(transpose(((transpose(transpose((transpose(X,-7) +transpose(X,7) ) ,4) ,4) +transpose((echo(transpose(((X+X) +transpose(echo(X,4,6) ,12) ) ,-5) ,4,6) |step((echo((X+X) ,4,6) +transpose((X+X) ,7) ) ,12) ) ,4) ) +transpose(transpose(((((X|X) +transpose(shuffle(X) ,4) ) +transpose(arpeggio(X) ,7) ) +transpose((arpeggio(X) |X) ,7) ) ,4) ,7) ) ,-7) |transpose(((((step((transpose((X|X) ,4) +(transpose(((X+((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose((X+transpose(X,12) ) ,7) ) ,-7) +(((transpose(X,-5) +transpose(X,7) ) +X) |transpose(X,-7) ) ) ) ,12) +((transpose(shuffle(transpose((X|X) ,-7) ) ,4) +transpose(arpeggio((((shuffle(X) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +step(X,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) +transpose((((X+transpose(shuffle(X) ,4) ) +transpose(shuffle(X) ,7) ) +transpose(arpeggio(X) ,7) ) ,12) ) ) ,4) ) +transpose(transpose((echo(X,4,6) |((transpose(X,-5) +transpose(step(transpose(X,-5) ,12) ,12) ) +(transpose(transpose(X,-5) ,-7) +(transpose(X,-5) +X) ) ) ) ,4) ,7) ) ) +transpose(transpose(transpose((transpose(transpose(X,-5) ,4) +step(((transpose(X,-7) +transpose((X+X) ,4) ) +transpose((X|X) ,7) ) ,12) ) ,-7) ,4) ,12) ) +transpose(transpose((step(((X|X) +transpose((X+transpose(X,7) ) ,-7) ) ,12) +((X|X) +transpose(X,-7) ) ) ,-5) ,4) ) +transpose((((((X+(X+transpose(X,7) ) ) +arpeggio((X+X) ) ) +((transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,-7) +transpose(X,4) ) +transpose(transpose(transpose(X,4) ,-5) ,7) ) ) +transpose(transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +(X+transpose(X,7) ) ) |shuffle(X) ) ,4) ,12) ) |transpose(transpose((transpose(((step(transpose(X,-5) ,12) +transpose(((transpose(X,-5) +transpose((X+X) ,12) ) +transpose(transpose(X,4) ,12) ) ,12) ) +transpose(transpose(((((transpose(X,-5) +transpose(((X+X) +transpose(X,7) ) ,4) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ,7) ) +transpose((transpose(X,4) |arpeggio(X) ) ,4) ) +transpose((((X+X) +transpose(X,4) ) +transpose((X+X) ,7) ) ,7) ) ,-5) ,7) ) ,-7) +transpose((((((X+X) |X) +transpose((X|X) ,4) ) +transpose(arpeggio((X+transpose((X+transpose(X,7) ) ,7) ) ) ,7) ) +transpose((X+X) ,7) ) ,-5) ) ,4) ,-5) ) ,7) ) ,-5) )
random seed used was 12 EXPR = ((transpose(transpose(shuffle(step((arpeggio(((echo((transpose(X,4) |((X+transpose(X,12) ) |(X|X) ) ) ,4,6) +transpose(step(X,12) ,7) ) +transpose(transpose(transpose(transpose(transpose((X+transpose((X+transpose(X,12) ) ,12) ) ,-5) ,-5) ,-5) ,-5) ,12) ) ) +transpose((((transpose(((X+X) +transpose(X,7) ) ,-7) +(echo(transpose((transpose(X,4) |transpose(X,4) ) ,-5) ,4,6) +(((X+X) |transpose(X,4) ) |X) ) ) +transpose(shuffle(step(((X|X) +arpeggio(X) ) ,12) ) ,4) ) +transpose(step(transpose((transpose(X,-5) +transpose(X,4) ) ,-7) ,12) ,7) ) ,7) ) ,12) ) ,-7) ,-5) |echo(shuffle(step(arpeggio(transpose((arpeggio(step(transpose(shuffle(transpose(arpeggio(X) ,4) ) ,4) ,12) ) +((((X|X) +transpose(X,4) ) +transpose(X,7) ) +(transpose((X+transpose((X|X) ,4) ) ,4) |transpose(shuffle((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,-5) ) ) ) ,-5) ) ,12) ) ,4,6) ) +((((echo(echo((((transpose(X,4) +transpose(transpose(X,-5) ,12) ) +transpose(((X|X) +(X+X) ) ,12) ) +transpose(echo((X|X) ,4,6) ,12) ) ,4,6) ,4,6) +transpose(echo(step(((transpose((arpeggio(echo(X,4,6) ) |transpose(X,-7) ) ,-5) |(arpeggio(X) +((transpose(X,-7) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(X,7) ) ) ) +(transpose((echo(transpose(X,-7) ,4,6) +(transpose(X,-5) |X) ) ,4) +transpose((transpose(X,-7) +transpose(X,-7) ) ,4) ) ) ,12) ,4,6) ,-5) ) +transpose(shuffle(transpose(shuffle(shuffle(((((transpose(((transpose(X,4) +transpose(arpeggio((arpeggio(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,4) +transpose(transpose(transpose(((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,12) ) ,-5) ,4) ,4) ) +transpose(transpose((transpose(X,-7) +X) ,-5) ,7) ) +transpose((((transpose((transpose(X,4) +transpose(X,7) ) ,-7) +transpose(transpose(echo(step((((transpose(X,-7) +transpose(step(X,12) ,4) ) +transpose(transpose(X,4) ,7) ) +(X+X) ) ,12) ,4,6) ,-5) ,4) ) +transpose(transpose(transpose(transpose(X,-7) ,-7) ,-5) ,7) ) +transpose(transpose((transpose((arpeggio(echo(X,4,6) ) +transpose(transpose(transpose(X,4) ,4) ,7) ) ,4) +transpose(shuffle(arpeggio(X) ) ,7) ) ,4) ,12) ) ,4) ) +transpose((shuffle(transpose(transpose(X,4) ,-5) ) +transpose(((((transpose((transpose(X,-7) |X) ,-5) +transpose(((transpose((X|X) ,-7) +transpose(X,7) ) |X) ,12) ) +transpose((((transpose(transpose(echo(X,4,6) ,-7) ,-5) +transpose(transpose((X+transpose(X,12) ) ,4) ,-7) ) +transpose((transpose(X,-5) +(arpeggio(X) |(X|X) ) ) ,4) ) +transpose((shuffle(((X|X) +shuffle(X) ) ) +transpose((X+transpose((X+X) ,12) ) ,7) ) ,7) ) ,4) ) +transpose(transpose((((((X+transpose(X,4) ) +transpose(X,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose((X+transpose(X,12) ) ,12) ) +transpose(transpose(echo(X,4,6) ,-5) ,-5) ) ,4) ,7) ) +transpose((((arpeggio(shuffle(shuffle(X) ) ) +transpose(((X+transpose((X|X) ,4) ) +transpose(echo(X,4,6) ,7) ) ,12) ) +transpose(step((X+transpose(arpeggio(transpose(X,4) ) ,7) ) ,12) ,12) ) +transpose((((X|X) +transpose(((X+arpeggio(X) ) +((X+transpose(X,12) ) |shuffle(X) ) ) ,4) ) +transpose(transpose(X,4) ,7) ) ,12) ) ,12) ) ,12) ) ,7) ) ) ) ,-7) ) ,7) ) +transpose(((((((((transpose(((transpose((transpose(X,4) +X) ,-7) +transpose(step((shuffle(X) |X) ,12) ,4) ) +transpose((((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,7) ) +((transpose(X,-5) +transpose((X+transpose(X,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,7) ) ,-7) +echo((X|X) ,4,6) ) +transpose(((echo((step(X,12) +X) ,4,6) |transpose(step(X,12) ,-5) ) +transpose(transpose(arpeggio(transpose(X,-7) ) ,-5) ,-7) ) ,4) ) +transpose(((shuffle(transpose(X,4) ) +transpose(echo(transpose((X|X) ,-5) ,4,6) ,7) ) +transpose(step(transpose(transpose((X+X) ,-5) ,-7) ,12) ,12) ) ,7) ) |(shuffle(((((X+X) +(X+X) ) +transpose(arpeggio(X) ,4) ) +transpose(shuffle((transpose(X,4) +X) ) ,7) ) ) +transpose(transpose(transpose(arpeggio(X) ,4) ,-5) ,12) ) ) +transpose(arpeggio(echo(((X+X) |step((((X|X) +(X+X) ) |((X+transpose(X,12) ) |arpeggio(X) ) ) ,12) ) ,4,6) ) ,4) ) +transpose((echo(((X+transpose(arpeggio((X+X) ) ,4) ) +transpose((((X+transpose(X,7) ) +transpose((X+transpose(X,7) ) ,4) ) +transpose(X,7) ) ,7) ) ,4,6) +echo((echo(step(X,12) ,4,6) +transpose((echo(X,4,6) +(X|X) ) ,7) ) ,4,6) ) ,7) ) |step((shuffle(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,-7) ) +transpose((echo((transpose(transpose(X,4) ,4) +transpose(transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) |transpose(X,4) ) ,4) ,7) ) ,4,6) +transpose(transpose(transpose(X,-5) ,4) ,12) ) ,7) ) ,12) ) +(transpose(((((arpeggio(transpose(step(X,12) ,4) ) +transpose((transpose(echo(echo(X,4,6) ,4,6) ,4) +transpose(transpose(X,4) ,12) ) ,4) ) +transpose(shuffle(((transpose(X,4) |((X+X) |echo(X,4,6) ) ) |transpose((X|X) ,4) ) ) ,7) ) |(transpose((arpeggio(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +((echo((X+transpose(X,7) ) ,4,6) +transpose(transpose((X+X) ,-7) ,7) ) +transpose((transpose(X,-7) +transpose(arpeggio(transpose(X,4) ) ,12) ) ,7) ) ) ,-5) +transpose(transpose((transpose(step(transpose(X,-5) ,12) ,-7) +(transpose(step(X,12) ,-5) +((X+X) |transpose(X,4) ) ) ) ,4) ,7) ) ) +transpose(((transpose(step(X,12) ,-7) +((transpose(X,4) +transpose((transpose(X,-7) +step(X,12) ) ,12) ) +transpose((((transpose(X,-5) |X) +transpose(transpose(X,-7) ,4) ) +transpose(X,7) ) ,7) ) ) +(transpose(echo(((transpose(X,4) +transpose(transpose(X,-7) ,4) ) +transpose(X,7) ) ,4,6) ,-7) +transpose(echo((X|X) ,4,6) ,-5) ) ) ,-7) ) ,4) |(transpose(transpose((transpose((X+transpose((transpose(X,-7) |step(X,12) ) ,7) ) ,-5) |((((step(X,12) +transpose(shuffle(transpose(X,-5) ) ,4) ) +transpose(((transpose(X,-5) +transpose(transpose(X,-5) ,4) ) +transpose(transpose(X,-7) ,7) ) ,7) ) +transpose((echo(X,4,6) +transpose((transpose(X,4) +X) ,12) ) ,4) ) +transpose(transpose((X+transpose(transpose(X,4) ,12) ) ,4) ,7) ) ) ,4) ,4) +arpeggio((((transpose((X+step(X,12) ) ,-5) |(step(X,12) +transpose((X+X) ,12) ) ) |((transpose(X,-5) +transpose(X,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) |((transpose(transpose(transpose(step(transpose(step(X,12) ,4) ,12) ,-7) ,-5) ,-7) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) |X) |(transpose(transpose(X,-5) ,-5) +X) ) ,4) ) +transpose(transpose((echo(X,4,6) +transpose(X,7) ) ,-7) ,7) ) ) ) ) ) ) ,4) ) +transpose(arpeggio((transpose(((shuffle(transpose(shuffle(((transpose((X+transpose(X,12) ) ,-7) +transpose(transpose(arpeggio(arpeggio(X) ) ,-7) ,4) ) +transpose(((X|X) +(X+transpose(X,12) ) ) ,7) ) ) ,4) ) +transpose(transpose((transpose((transpose(transpose(X,4) ,-5) +transpose(echo(shuffle(shuffle((X+transpose((X+transpose(X,12) ) ,12) ) ) ) ,4,6) ,12) ) ,-5) +transpose(transpose(shuffle(transpose(step((X+transpose(X,12) ) ,12) ,4) ) ,4) ,4) ) ,4) ,4) ) +transpose(arpeggio(transpose((arpeggio(echo((X+X) ,4,6) ) |echo(((X|X) |((X+transpose(transpose((X+X) ,-7) ,4) ) +transpose(arpeggio((X+transpose(X,12) ) ) ,7) ) ) ,4,6) ) ,4) ) ,7) ) ,-7) +transpose(shuffle(((transpose(transpose((shuffle(transpose(X,4) ) |((X+X) +transpose(X,7) ) ) ,4) ,-5) |((((X+X) +(X+X) ) +transpose((transpose(X,4) +step(X,12) ) ,7) ) +step((X+((X+X) |X) ) ,12) ) ) +transpose((((transpose(transpose(step(X,12) ,-5) ,-7) +transpose((transpose(X,-7) +transpose((X|X) ,-5) ) ,12) ) +transpose(transpose(arpeggio(X) ,-7) ,4) ) +transpose(transpose(transpose(transpose(X,4) ,-7) ,-5) ,7) ) ,4) ) ) ,7) ) ) ,7) ) )
random seed used was 0 EXPR = transpose((((((shuffle((transpose(step(transpose(echo(transpose(X,-7) ,4,6) ,4) ,12) ,-5) +transpose(((transpose((((X+X) +echo((X+X) ,4,6) ) +transpose(X,-5) ) ,-7) +echo(shuffle(((transpose(X,-5) +transpose((X|X) ,4) ) +transpose(transpose(X,-5) ,7) ) ) ,4,6) ) +transpose(echo((transpose(X,-5) |step(X,12) ) ,4,6) ,-5) ) ,4) ) ) +transpose(((transpose((transpose(step((X+transpose(X,12) ) ,12) ,-7) +((echo((transpose(X,-7) +transpose((X|X) ,12) ) ,4,6) +((transpose(arpeggio(X) ,4) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +X) ,4) ) +transpose((X|X) ,7) ) ) +transpose(transpose(((transpose(X,-5) +transpose(transpose(X,-5) ,7) ) +echo(X,4,6) ) ,-5) ,7) ) ) ,-7) +transpose(shuffle(arpeggio(arpeggio(((X|echo(X,4,6) ) +shuffle(((X|X) |transpose(X,-7) ) ) ) ) ) ) ,4) ) +transpose(shuffle(arpeggio(((transpose(X,-7) +(X+transpose(transpose(X,-5) ,12) ) ) +(((transpose(X,-7) +transpose(X,12) ) +transpose(echo((transpose(X,4) |X) ,4,6) ,4) ) +transpose((step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) +X) ,7) ) ) ) ) ,7) ) ,4) ) +transpose((((((shuffle((X+transpose(X,12) ) ) +transpose((((X|X) +(X+transpose((X+transpose(X,7) ) ,7) ) ) +transpose(transpose(((X+transpose(X,7) ) +X) ,-5) ,12) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) |transpose((shuffle(X) +(X+X) ) ,-7) ) |((((transpose((X|shuffle(X) ) ,4) +transpose(((X+transpose(step((X+X) ,12) ,4) ) +transpose(echo(shuffle(X) ,4,6) ,7) ) ,7) ) +transpose(transpose((((X+X) +transpose((X+transpose(X,12) ) ,4) ) +transpose((X+X) ,7) ) ,-7) ,12) ) +transpose(transpose((X+X) ,-5) ,-5) ) +transpose(transpose(step((((X+transpose(X,12) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose(echo((((X|X) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,4,6) ,12) ) ,12) ,-5) ,12) ) ) |step(transpose((((echo(X,4,6) +transpose((X+(X+transpose(X,7) ) ) ,7) ) +transpose(transpose(((X+step(X,12) ) +transpose(X,12) ) ,4) ,4) ) +transpose((echo(X,4,6) +transpose(transpose(X,-5) ,-7) ) ,7) ) ,-7) ,12) ) ,7) ) +transpose((((transpose(transpose((X+X) ,-7) ,-5) |(((shuffle(step(shuffle(X) ,12) ) |(transpose((X+transpose(X,12) ) ,-7) |(X+transpose(X,7) ) ) ) +transpose(arpeggio(((X+(shuffle(X) +transpose(((X|X) |arpeggio(X) ) ,12) ) ) +(transpose((X|X) ,4) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +X) ,12) ) ) ) ,4) ) +transpose(transpose(transpose(((arpeggio(transpose(X,-5) ) +transpose(transpose(transpose(X,-5) ,-5) ,4) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) |(X+X) ) ,7) ) ,4) ,-5) ,7) ) ) |((X+X) +transpose(shuffle(transpose((X|X) ,-7) ) ,12) ) ) +transpose((shuffle((transpose((shuffle(step(transpose(transpose(X,-5) ,4) ,12) ) +transpose((((X+transpose(X,7) ) +transpose(X,12) ) +transpose(transpose(step(X,12) ,-5) ,7) ) ,7) ) ,-7) +(transpose((shuffle(transpose(transpose(X,-7) ,-7) ) |transpose(((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose((X+transpose(transpose(X,-5) ,12) ) ,7) ) ,-5) ) ,4) +transpose(transpose(X,-5) ,12) ) ) ) +((echo((step(X,12) +X) ,4,6) |step(step(step(X,12) ,12) ,12) ) +transpose(transpose((echo(((transpose(arpeggio(X) ,-5) +transpose((X+transpose(X,12) ) ,4) ) +transpose((X+transpose((X+transpose(X,7) ) ,7) ) ,7) ) ,4,6) +transpose(echo((X+transpose(X,7) ) ,4,6) ,12) ) ,4) ,12) ) ) ,12) ) ,4) ) +transpose((echo((transpose((transpose((transpose(X,-7) |(X+X) ) ,4) +(((step(X,12) +((X|X) |echo(X,4,6) ) ) +transpose(shuffle(shuffle(X) ) ,12) ) |transpose((X+transpose(transpose(X,-5) ,7) ) ,-7) ) ) ,4) |step(transpose((((echo(transpose(transpose(X,-5) ,-7) ,4,6) +transpose(transpose(X,4) ,7) ) +transpose(((step(X,12) +transpose((X+transpose(X,7) ) ,4) ) +transpose(arpeggio(X) ,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-5) ,12) ) ,4,6) +transpose((transpose(((((step((X+transpose(X,7) ) ,12) +transpose((transpose((X+transpose(X,12) ) ,-7) +transpose((X|X) ,12) ) ,7) ) +transpose(((X+transpose(X,12) ) +transpose(((X+transpose((arpeggio(X) |(X+X) ) ,12) ) +((X|X) |echo(X,4,6) ) ) ,12) ) ,7) ) +transpose(step((transpose(arpeggio(X) ,4) |(echo((X|X) ,4,6) +transpose(step(X,12) ,7) ) ) ,12) ,4) ) +transpose(transpose((X+transpose(echo((X+transpose(X,12) ) ,4,6) ,7) ) ,-7) ,7) ) ,-7) +echo(transpose(X,-7) ,4,6) ) ,7) ) ,7) ) +transpose((((transpose((transpose(transpose(transpose(echo(X,4,6) ,-7) ,-5) ,-5) |shuffle(transpose((arpeggio(X) +transpose(X,7) ) ,-5) ) ) ,-5) +((transpose((step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) +transpose(step((X+transpose(X,12) ) ,12) ,12) ) ,-5) +transpose((echo((transpose((transpose(X,-7) |X) ,-5) |transpose(transpose(echo((X+transpose(X,12) ) ,4,6) ,4) ,4) ) ,4,6) +transpose(transpose(((shuffle(X) +(X+X) ) +transpose(transpose(X,4) ,7) ) ,-7) ,12) ) ,4) ) +transpose((transpose((transpose(transpose((X|X) ,-5) ,4) +transpose(echo(transpose(X,-7) ,4,6) ,7) ) ,4) +transpose(transpose((shuffle(transpose(transpose(X,4) ,-5) ) +transpose(arpeggio(transpose((transpose(X,-7) +((X+transpose(X,7) ) +(X+X) ) ) ,-7) ) ,12) ) ,-7) ,12) ) ,7) ) ) +transpose(transpose(transpose(((X|X) |(X|X) ) ,-5) ,-5) ,7) ) |transpose(transpose((arpeggio((transpose(transpose(transpose(X,-7) ,-7) ,-7) +transpose(transpose((X|X) ,4) ,12) ) ) +(((transpose(arpeggio(X) ,4) +transpose(((transpose(X,-7) +transpose(shuffle(X) ,7) ) +(X+transpose(X,7) ) ) ,7) ) +transpose(transpose(X,4) ,12) ) +transpose((((transpose((X|X) ,-5) +(transpose(echo(X,4,6) ,-7) +transpose((X+((X+transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ) ,12) ) ) +transpose(transpose(shuffle((X+transpose(transpose(X,-5) ,7) ) ) ,-5) ,4) ) +transpose(arpeggio(transpose((X|X) ,-7) ) ,7) ) ,12) ) ) ,-7) ,-5) ) ,12) ) ,-5)
random seed used was 0 EXPR = ((shuffle(transpose(transpose(transpose(X,4) ,-5) ,-7) ) |(transpose(transpose((transpose((transpose(((X|((X+X) +transpose((X+X) ,12) ) ) |transpose(arpeggio(X) ,-7) ) ,4) +transpose((transpose((X+X) ,4) +arpeggio(X) ) ,7) ) ,-7) +transpose(((transpose(transpose(transpose(X,4) ,4) ,-7) |transpose(transpose(transpose(((transpose(X,4) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,4) ,-5) ,4) ) +transpose(arpeggio((((X|X) +transpose((transpose(X,-5) +transpose(X,-7) ) ,4) ) +transpose(X,7) ) ) ,-5) ) ,7) ) ,-5) ,-7) |transpose(transpose(transpose(((((((X+transpose((X+X) ,4) ) +transpose(step(X,12) ,7) ) |transpose((X+transpose((X+transpose(X,7) ) ,12) ) ,4) ) |transpose(transpose(transpose(X,-5) ,4) ,-7) ) +transpose(transpose((transpose(transpose(step((X+X) ,12) ,-5) ,-7) +transpose(transpose(transpose(X,4) ,-5) ,7) ) ,-5) ,4) ) +transpose(((arpeggio(X) +transpose(step(X,12) ,12) ) +transpose(transpose(transpose(shuffle(transpose((X+X) ,4) ) ,4) ,-5) ,12) ) ,7) ) ,-7) ,4) ,4) ) ) +echo(arpeggio(transpose(transpose(echo(shuffle(arpeggio(X) ) ,4,6) ,-5) ,-7) ) ,4,6) )
random seed used was 0

The algorithm for Expresso is written in KeyKit, and here's the source code.