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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Phrase for X:
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After 20 generations the expression "X" became this:
(transpose((transpose(((transpose((transpose(transpose(transpose(((transpose(((transpose(echo(X,4,6) ,4) +transpose((X+transpose(echo(X,4,6) ,7) ) ,4) ) +transpose(step(X,12) ,7) ) ,-5) +transpose(shuffle(((transpose(X,-7) +transpose(transpose((X+transpose(X,7) ) ,4) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,4) ) +transpose((transpose((X|X) ,-5) +transpose(transpose(X,4) ,4) ) ,7) ) ,-7) ,-5) ,4) +(transpose((transpose((transpose(((X+transpose(echo(X,4,6) ,4) ) +transpose(transpose(X,4) ,7) ) ,-5) +transpose(transpose(arpeggio(transpose((X+transpose(X,7) ) ,-5) ) ,4) ,12) ) ,4) +transpose(transpose(arpeggio(arpeggio((((X|X) +X) +transpose(transpose(X,4) ,-5) ) ) ) ,-7) ,7) ) ,-5) +echo((((((arpeggio(transpose(X,-7) ) +transpose((X+X) ,7) ) +shuffle(((transpose(X,-7) +transpose(X,12) ) |X) ) ) +step(transpose(step((transpose(X,-7) |(arpeggio(X) +(X+transpose(X,7) ) ) ) ,12) ,4) ,12) ) +transpose((transpose((echo(transpose(X,-7) ,4,6) +transpose((X|transpose(X,-7) ) ,7) ) ,-7) +transpose(transpose(transpose(echo(transpose(((X|X) +transpose(echo(X,4,6) ,12) ) ,4) ,4,6) ,-7) ,-5) ,12) ) ,4) ) +transpose(shuffle((arpeggio(step(X,12) ) +(transpose((transpose(X,-7) +transpose(transpose((X+transpose(X,7) ) ,-7) ,12) ) ,-7) +transpose((transpose((((X|X) +transpose(arpeggio(X) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-7) |(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) ) ,12) ) ) ) ,7) ) ,4,6) ) ) ,-7) +transpose((transpose(((step((transpose((echo(X,4,6) +X) ,-5) +((((((X+X) |step(X,12) ) |(transpose((X+transpose(X,12) ) ,-5) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,7) ) ) |step(transpose(X,4) ,12) ) +transpose(echo(arpeggio(transpose(X,-5) ) ,4,6) ,4) ) +transpose(transpose(arpeggio(((X+X) +transpose((transpose(X,-5) +transpose(X,4) ) ,12) ) ) ,4) ,7) ) ) ,12) +transpose(step(transpose(((transpose(transpose((arpeggio(X) |transpose(X,4) ) ,-5) ,4) +transpose(arpeggio((((transpose(X,4) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) |step(X,12) ) ) ,4) ) +transpose(transpose(arpeggio((X+transpose(X,7) ) ) ,-7) ,7) ) ,-5) ,12) ,12) ) |(((step((((X+transpose(X,7) ) +transpose((X+X) ,4) ) +transpose(transpose(X,-7) ,7) ) ,12) +transpose(transpose(((X|(X+transpose(X,12) ) ) +shuffle((X+transpose(X,12) ) ) ) ,4) ,-7) ) +transpose(echo(arpeggio((step(X,12) +transpose(transpose(step(X,12) ,4) ,12) ) ) ,4,6) ,4) ) +transpose(transpose((((transpose(X,4) +transpose((step((X+transpose(X,7) ) ,12) +transpose(X,7) ) ,7) ) +transpose(step(((transpose(X,4) +step((X+X) ,12) ) +transpose((transpose(X,4) |arpeggio(transpose(X,4) ) ) ,7) ) ,12) ,4) ) +transpose(((echo((transpose(X,-5) |transpose(transpose(X,-7) ,-5) ) ,4,6) +transpose(arpeggio(transpose(transpose(X,4) ,-7) ) ,4) ) +transpose(((step(X,12) +transpose(X,7) ) +(((transpose(X,-7) |X) +transpose(((transpose(X,4) +transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) ,4) ) +transpose(((transpose(X,-7) +transpose(X,4) ) +transpose((X+X) ,7) ) ,7) ) ) ,7) ) ,7) ) ,4) ,7) ) ) ,4) +transpose(transpose(echo(transpose(transpose(transpose(((((X+transpose(X,12) ) +transpose(transpose((X+X) ,-7) ,4) ) +transpose(step((X|X) ,12) ,7) ) +((transpose(X,4) |((X+transpose(X,4) ) +transpose(X,7) ) ) |X) ) ,4) ,-7) ,-7) ,4,6) ,-5) ,7) ) ,4) ) +transpose((step(echo(transpose(transpose(arpeggio(echo(((transpose(((X+transpose(X,12) ) +transpose(X,-7) ) ,-7) |transpose(transpose(echo(X,4,6) ,-5) ,4) ) +transpose(step((X+transpose(X,-7) ) ,12) ,12) ) ,4,6) ) ,4) ,4) ,4,6) ,12) +transpose(((((step(transpose(((step(((X+X) |(X+transpose(X,12) ) ) ,12) |(arpeggio(X) +transpose(echo(X,4,6) ,7) ) ) |transpose(shuffle(transpose(X,-7) ) ,4) ) ,-5) ,12) +shuffle((X|X) ) ) +transpose(transpose(transpose(((((X+X) +transpose(step(echo(X,4,6) ,12) ,7) ) +transpose((echo((((arpeggio(shuffle(X) ) +transpose(arpeggio(X) ,-7) ) +transpose(transpose((X+X) ,4) ,4) ) +transpose(echo((transpose(X,-5) +X) ,4,6) ,7) ) ,4,6) +transpose(transpose((X+X) ,-5) ,4) ) ,4) ) +transpose(transpose(X,4) ,7) ) ,-5) ,4) ,12) ) +transpose(arpeggio((echo(transpose(((transpose(X,4) +transpose(((X|X) |X) ,12) ) +transpose(transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,4) ,7) ) ,4) ,4,6) +transpose(transpose(transpose((echo(X,4,6) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+X) ,7) ) +(X+X) ) ,7) ) ,4) ,4) ,12) ) ) ,4) ) +transpose(step(echo((transpose(arpeggio(shuffle(step(transpose(X,4) ,12) ) ) ,-5) |step((shuffle(echo(echo(X,4,6) ,4,6) ) +(((((X+transpose(X,7) ) +transpose(transpose(X,4) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) +transpose(X,12) ) |(transpose(X,4) +transpose(X,7) ) ) ) ,12) ) ,4,6) ,12) ,7) ) ,-5) ) ,7) ) ,4) +transpose(step(shuffle((arpeggio(transpose(((transpose((transpose(X,-5) +(((X+transpose(X,4) ) +transpose(X,7) ) |(X+transpose(X,12) ) ) ) ,-5) +(transpose(echo(transpose(((X+transpose(((X+transpose(X,7) ) |X) ,4) ) +transpose(shuffle(X) ,7) ) ,4) ,4,6) ,4) +(transpose(((echo(X,4,6) +transpose(X,4) ) +transpose(X,7) ) ,-5) +transpose(echo((transpose(X,-7) |X) ,4,6) ,12) ) ) ) |((arpeggio(transpose(echo(transpose((((echo(X,4,6) |(shuffle(step(X,12) ) +transpose((X+transpose(X,7) ) ,4) ) ) |transpose((((X+transpose(X,4) ) +transpose(X,7) ) |step(X,12) ) ,-5) ) +transpose(arpeggio((((transpose(X,4) +transpose((X+X) ,4) ) +transpose(transpose(X,-7) ,7) ) +transpose(((X|X) +transpose(((X+transpose(X,12) ) +transpose((X+X) ,12) ) ,7) ) ,7) ) ) ,7) ) ,4) ,4,6) ,-7) ) +transpose(transpose(echo((((transpose((X|X) ,4) +echo((X+transpose(X,7) ) ,4,6) ) +transpose(transpose(transpose(((X|X) +(X+transpose(X,7) ) ) ,-5) ,4) ,4) ) +transpose((((X+transpose(X,12) ) |echo(X,4,6) ) +transpose((X|X) ,12) ) ,7) ) ,4,6) ,-7) ,4) ) +transpose((((echo(transpose(X,-5) ,4,6) +transpose((((X+X) +transpose((transpose(X,-7) |X) ,12) ) +transpose(((shuffle(transpose(X,4) ) +transpose(transpose((arpeggio(X) +transpose(arpeggio(X) ,12) ) ,-7) ,4) ) +transpose(X,7) ) ,7) ) ,7) ) +transpose(arpeggio(shuffle((X+transpose(X,12) ) ) ) ,4) ) +transpose(transpose((((X+transpose(arpeggio(X) ,12) ) +transpose(transpose(arpeggio(X) ,4) ,7) ) +step(transpose(transpose(X,4) ,-5) ,12) ) ,4) ,7) ) ,7) ) ) ,-7) ) |arpeggio(transpose((arpeggio(step(((transpose(((X+X) +transpose((X+transpose(X,12) ) ,-7) ) ,-5) |step(shuffle((X+transpose(X,7) ) ) ,12) ) +echo((((X+transpose(X,12) ) +transpose((arpeggio(X) |transpose((X+X) ,4) ) ,4) ) +transpose(step(shuffle(shuffle(X) ) ,12) ,7) ) ,4,6) ) ,12) ) +transpose(transpose((((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) |((X+transpose(X,4) ) +transpose(X,7) ) ) +arpeggio(transpose(X,-5) ) ) |((shuffle(X) +transpose(transpose((echo(X,4,6) |step((X|X) ,12) ) ,4) ,12) ) |(step((X|(X+X) ) ,12) +transpose(transpose(transpose(X,4) ,-5) ,-5) ) ) ) ,-5) ,12) ) ,4) ) ) ) ,12) ,7) ) ,4) +((((((transpose(step(arpeggio(transpose(X,-7) ) ,12) ,-7) +(transpose((shuffle(transpose(shuffle(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ,-7) ) |(transpose((transpose(X,-5) |(transpose((X+transpose(X,7) ) ,-5) +transpose(shuffle((X+transpose((X+X) ,7) ) ) ,7) ) ) ,-5) +transpose((((arpeggio((X+X) ) +transpose(((X|X) +transpose(transpose(X,-5) ,12) ) ,12) ) +transpose(transpose(transpose(transpose((X+transpose(X,12) ) ,-5) ,4) ,-5) ,12) ) +(arpeggio(transpose(X,-7) ) +arpeggio(transpose(X,-5) ) ) ) ,7) ) ) ,-7) +transpose(((shuffle(step(step(X,12) ,12) ) +transpose((transpose(transpose(transpose(((X+X) |(X+X) ) ,-7) ,-7) ,-5) +(((X+transpose(X,12) ) +transpose(transpose(X,4) ,7) ) +transpose(transpose(arpeggio((transpose(X,4) +transpose((X|X) ,12) ) ) ,-7) ,12) ) ) ,4) ) +transpose(((arpeggio(echo(transpose(X,4) ,4,6) ) +transpose(transpose(transpose(((X|X) +transpose(transpose(X,-5) ,4) ) ,-7) ,4) ,7) ) +transpose(transpose(X,-5) ,-7) ) ,7) ) ,7) ) ) +(transpose(shuffle(transpose(((X+transpose(((transpose(X,-7) +transpose((X+transpose(X,12) ) ,4) ) +transpose(((X|X) +X) ,7) ) ,7) ) +((X+transpose(X,12) ) |transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ) ) ,-7) ) ,-5) |transpose(transpose(((step(echo(((X+X) +transpose(X,12) ) ,4,6) ,12) |(transpose((X+X) ,4) +arpeggio(transpose(transpose(X,4) ,-5) ) ) ) +((transpose(X,4) +transpose(transpose(echo(X,4,6) ,4) ,12) ) +((arpeggio(arpeggio(X) ) +(X+transpose((X+X) ,7) ) ) +transpose((shuffle(X) +transpose(X,4) ) ,7) ) ) ) ,4) ,-5) ) ) |transpose((transpose((transpose(shuffle(X) ,4) +transpose(transpose(echo(((transpose(X,-7) +transpose((X+X) ,4) ) +transpose(arpeggio(X) ,7) ) ,4,6) ,4) ,7) ) ,-7) +transpose((echo(echo(((transpose(X,4) |X) +transpose(transpose((X+transpose(X,7) ) ,-7) ,-7) ) ,4,6) ,4,6) +transpose((transpose(shuffle(((echo((arpeggio(arpeggio(X) ) +(((X+transpose(X,12) ) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,-7) ,7) ) ) ,4,6) +transpose(transpose(transpose((X+X) ,-7) ,-7) ,4) ) +transpose(transpose(transpose(transpose(transpose(X,4) ,4) ,-5) ,-7) ,7) ) ) ,-7) +transpose(shuffle((((transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,-7) |arpeggio(((X+transpose(transpose(X,-5) ,7) ) +transpose(X,12) ) ) ) +transpose((((transpose(((X+X) +transpose(X,12) ) ,-7) +transpose(step(transpose((X+transpose(X,12) ) ,-7) ,12) ,4) ) +transpose(echo((X|X) ,4,6) ,7) ) +step(transpose((((X+X) +transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,-5) ,12) ) ,4) ) +transpose(transpose(transpose(transpose(X,-5) ,4) ,4) ,7) ) ) ,7) ) ,7) ) ,12) ) ,-5) ) +transpose(echo((shuffle(transpose(step((transpose(((transpose(X,-7) |transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-7) ) +transpose((step(X,12) +shuffle(transpose(X,-5) ) ) ,7) ) ,-7) +((echo(transpose(transpose((X+transpose(X,12) ) ,-7) ,-5) ,4,6) +(transpose(X,-5) +transpose((transpose(X,-7) |step(X,12) ) ,7) ) ) +transpose(step(transpose((X+transpose(X,12) ) ,-5) ,12) ,12) ) ) ,12) ,4) ) |transpose(arpeggio(((transpose(transpose(arpeggio(transpose(transpose(((X+transpose(X,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,-7) ,4) ) ,4) ,4) +transpose((transpose(transpose((echo(X,4,6) +X) ,-7) ,-5) +transpose((step(shuffle(transpose(X,4) ) ,12) +(((transpose(X,4) +(X+X) ) +transpose(X,7) ) +((transpose(X,-7) +transpose(shuffle(X) ,4) ) +transpose(transpose(echo(X,4,6) ,4) ,7) ) ) ) ,12) ) ,4) ) +transpose(transpose(echo(transpose(arpeggio(X) ,4) ,4,6) ,-5) ,7) ) ) ,-5) ) ,4,6) ,-5) ) +transpose(((echo((transpose((((echo((transpose(transpose(transpose(X,-7) ,-5) ,4) +(step((transpose(X,-7) +X) ,12) +transpose((X+transpose(arpeggio(X) ,7) ) ,7) ) ) ,4,6) +(shuffle((transpose(X,4) |transpose(transpose(transpose(X,-5) ,4) ,-5) ) ) |(X+transpose(X,12) ) ) ) +transpose(arpeggio(transpose((((arpeggio(X) +transpose(X,4) ) +transpose(X,7) ) |transpose(X,-7) ) ,4) ) ,4) ) +transpose(transpose(((echo((X+X) ,4,6) +(X+transpose(transpose(X,-5) ,12) ) ) |transpose(transpose((X+transpose(X,7) ) ,-7) ,-5) ) ,-7) ,7) ) ,4) +((transpose(transpose(arpeggio(echo(echo(X,4,6) ,4,6) ) ,-7) ,-5) +transpose(echo(transpose(shuffle(X) ,-5) ,4,6) ,4) ) +transpose((shuffle((echo((step(X,12) +transpose(X,12) ) ,4,6) +transpose(transpose(transpose(arpeggio(X) ,4) ,4) ,12) ) ) +transpose((step(shuffle(X) ,12) +transpose(transpose(X,4) ,7) ) ,4) ) ,7) ) ) ,4,6) +transpose(step(transpose((shuffle((transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,-7) +transpose(transpose((((X+transpose(X,12) ) |(X+transpose(X,7) ) ) +((shuffle(X) +(echo(X,4,6) +(X+X) ) ) +transpose(((step(X,12) +transpose(X,12) ) +X) ,-7) ) ) ,-5) ,7) ) ) |shuffle((((X+transpose(X,12) ) +transpose(echo((X|X) ,4,6) ,7) ) |transpose(step(shuffle(X) ,12) ,-7) ) ) ) ,-7) ,12) ,4) ) +transpose(step(step(transpose(transpose(arpeggio(arpeggio(transpose((transpose((X+transpose(X,7) ) ,-7) |(X+transpose(X,7) ) ) ,-7) ) ) ,4) ,-7) ,12) ,12) ,7) ) ,7) ) +(shuffle(transpose((transpose(echo(((shuffle((transpose((arpeggio(X) +transpose((transpose(X,4) +transpose(X,7) ) ,12) ) ,-7) +transpose(shuffle(transpose(transpose(transpose(X,4) ,4) ,4) ) ,7) ) ) +transpose(((arpeggio((step(transpose(transpose(X,-7) ,-7) ,12) |((transpose(echo(X,4,6) ,-7) |transpose(X,-5) ) +X) ) ) +transpose(arpeggio(echo((arpeggio(X) +transpose((X+X) ,12) ) ,4,6) ) ,4) ) +transpose(((transpose(X,-5) +transpose((X+X) ,7) ) |(X+echo((X+X) ,4,6) ) ) ,7) ) ,4) ) +transpose(arpeggio(transpose(transpose(X,4) ,-5) ) ,7) ) ,4,6) ,4) +transpose(arpeggio(echo(((transpose((transpose(transpose(transpose(arpeggio(X) ,4) ,-7) ,-7) |transpose(transpose(transpose(X,4) ,-5) ,4) ) ,-5) +transpose(transpose(transpose(transpose(shuffle(step(X,12) ) ,-7) ,4) ,-5) ,4) ) +transpose(((((transpose(X,-5) +((transpose(transpose(X,-7) ,-5) +transpose(shuffle(arpeggio(transpose(X,-7) ) ) ,4) ) +transpose(transpose(step(X,12) ,-5) ,7) ) ) |(arpeggio(X) +transpose(((X|X) +(X+transpose(X,7) ) ) ,12) ) ) +transpose(((X+(X+transpose(X,7) ) ) |echo(shuffle(echo(X,4,6) ) ,4,6) ) ,4) ) +transpose((echo(step(X,12) ,4,6) +transpose(transpose(((X+transpose(X,12) ) |(X|X) ) ,-5) ,12) ) ,7) ) ,7) ) ,4,6) ) ,7) ) ,-5) ) |(transpose((shuffle(((((X+transpose(transpose(transpose(X,4) ,4) ,4) ) +transpose(transpose(((((X+transpose(X,7) ) +transpose(step(X,12) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ,-7) ,7) ) +transpose((transpose(((X+transpose(X,12) ) |transpose(X,-7) ) ,-7) +transpose((transpose((transpose(X,4) +X) ,4) +transpose(step((X+X) ,12) ,-7) ) ,12) ) ,4) ) |(transpose((X+transpose(X,12) ) ,-5) |(((X+transpose(X,4) ) +transpose((X+X) ,7) ) |echo((X+transpose(X,12) ) ,4,6) ) ) ) ) +(((step((arpeggio((((transpose(echo(X,4,6) ,4) +transpose(step(X,12) ,4) ) +transpose((X+(X+transpose(X,12) ) ) ,7) ) |step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) +transpose(step((((X|X) +transpose(transpose(X,-7) ,7) ) +transpose(echo(transpose(X,4) ,4,6) ,7) ) ,12) ,12) ) ,12) |(transpose(transpose((transpose(transpose(X,4) ,4) +transpose((transpose(X,-7) |(X|X) ) ,12) ) ,-7) ,4) +transpose((transpose((X+(((X+transpose(X,4) ) +transpose(X,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,-5) +transpose(arpeggio(transpose(X,-7) ) ,-5) ) ,7) ) ) +transpose(transpose(transpose(transpose((shuffle((X+X) ) +echo(arpeggio((X+transpose(X,7) ) ) ,4,6) ) ,-7) ,-7) ,4) ,7) ) +transpose(((transpose(transpose(transpose(arpeggio((arpeggio(X) +transpose(X,12) ) ) ,-5) ,-7) ,-7) +transpose(step(transpose(arpeggio((X|transpose(X,-5) ) ) ,-7) ,12) ,12) ) +transpose((shuffle(((transpose(X,-7) +transpose(transpose(X,4) ,4) ) +transpose(shuffle(X) ,7) ) ) |(((transpose((X+X) ,4) +transpose(arpeggio(shuffle(transpose((X+transpose(X,7) ) ,4) ) ) ,7) ) +transpose(arpeggio((transpose(X,-7) +transpose((transpose(X,-5) |X) ,12) ) ) ,7) ) +transpose(echo(transpose(transpose((transpose(transpose(X,-7) ,-5) +transpose(X,7) ) ,-5) ,4) ,4,6) ,7) ) ) ,7) ) ,12) ) ) ,-5) +transpose((transpose((arpeggio((transpose(transpose(echo(transpose(X,-5) ,4,6) ,-5) ,-5) +arpeggio((((shuffle(transpose(((X+transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,-5) ) +transpose(X,4) ) +transpose((transpose(transpose(X,-7) ,4) +transpose(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ,7) ) +transpose(arpeggio((((X+X) |transpose((X+transpose(X,7) ) ,-7) ) |(arpeggio(arpeggio(X) ) |transpose(X,-5) ) ) ) ,12) ) ) ) ) |(step(shuffle(X) ,12) |shuffle(transpose(step((((transpose(X,-7) +transpose(transpose(X,-5) ,4) ) +transpose(echo(X,4,6) ,7) ) +transpose(arpeggio(transpose(X,4) ) ,7) ) ,12) ,-5) ) ) ) ,4) +transpose(transpose((((((((echo(transpose(((X+transpose(X,12) ) |((X|X) +transpose((X+transpose(X,7) ) ,7) ) ) ,4) ,4,6) +transpose(shuffle(transpose((X+transpose(X,-7) ) ,-7) ) ,4) ) +transpose(transpose(echo(transpose(X,-7) ,4,6) ,-5) ,7) ) +transpose(transpose((transpose(transpose(transpose(X,4) ,-5) ,4) +(X|transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) ) ,-5) ,12) ) |transpose((transpose((X+transpose(X,12) ) ,-5) |X) ,4) ) +transpose(((transpose((((((X+transpose(X,12) ) +transpose(step(X,12) ,4) ) +transpose(X,7) ) +transpose(arpeggio((X+X) ) ,12) ) +transpose(transpose(X,-5) ,12) ) ,-7) +arpeggio((transpose(transpose(X,-7) ,4) |step(X,12) ) ) ) +transpose((step(arpeggio(arpeggio(shuffle(X) ) ) ,12) +transpose(step((transpose(X,4) +(shuffle(X) +transpose(transpose(X,4) ,12) ) ) ,12) ,12) ) ,7) ) ,4) ) +transpose(echo(transpose(transpose(((transpose(((transpose(X,-7) +X) |transpose(echo(X,4,6) ,-7) ) ,4) |echo(transpose((X|X) ,-7) ,4,6) ) +transpose((arpeggio((X+transpose(X,7) ) ) +transpose(shuffle(echo((X+X) ,4,6) ) ,-7) ) ,7) ) ,-5) ,-5) ,4,6) ,7) ) +transpose(((transpose((transpose(echo((X+transpose(X,12) ) ,4,6) ,4) +transpose(echo(X,4,6) ,4) ) ,4) +transpose(((transpose(X,-7) +transpose(arpeggio((X+transpose(transpose(X,4) ,12) ) ) ,4) ) +transpose((X+X) ,7) ) ,12) ) +transpose(((((X+X) +transpose(X,4) ) +transpose(arpeggio(X) ,7) ) |arpeggio(X) ) ,-5) ) ,12) ) ,-5) ,12) ) ,-5) ) ) ) )
random seed used was 239084812

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