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:
(((echo((((transpose((transpose(shuffle(step(X,12) ) ,-7) |(transpose(arpeggio((transpose(X,4) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,4) +shuffle(X) ) ) ,-5) +transpose(step(transpose(echo(((transpose(echo(X,4,6) ,4) +transpose((X+transpose(X,7) ) ,7) ) |transpose(X,-5) ) ,4,6) ,-5) ,12) ,4) ) +transpose(arpeggio(shuffle(step(((step(arpeggio(X) ,12) +transpose(echo(shuffle(transpose(X,-5) ) ,4,6) ,-5) ) +((X+((X|X) +X) ) |step(X,12) ) ) ,12) ) ) ,7) ) +transpose(arpeggio(shuffle(transpose((echo(arpeggio(X) ,4,6) |(shuffle(X) +arpeggio(step(arpeggio(transpose(X,4) ) ,12) ) ) ) ,-7) ) ) ,7) ) ,4,6) +transpose((arpeggio((transpose(shuffle(arpeggio((((step(step(X,12) ,12) +transpose((shuffle((echo(X,4,6) +transpose(X,7) ) ) |(step(X,12) +echo(arpeggio(X) ,4,6) ) ) ,7) ) +transpose(transpose(((transpose(X,-7) +transpose(X,7) ) |transpose(shuffle(X) ,-7) ) ,-5) ,12) ) |echo(transpose((transpose(X,-5) +transpose(X,4) ) ,-5) ,4,6) ) ) ) ,-7) +transpose(shuffle(transpose(echo(transpose(step(arpeggio((X+X) ) ,12) ,-5) ,4,6) ,4) ) ,4) ) ) +transpose(((transpose((((arpeggio(transpose(transpose(echo(X,4,6) ,-7) ,-5) ) |transpose((step(transpose(X,-5) ,12) |shuffle(X) ) ,-7) ) +transpose(shuffle(step((transpose(shuffle(shuffle(X) ) ,-5) +(transpose((X+(X+transpose(X,7) ) ) ,4) |arpeggio(X) ) ) ,12) ) ,12) ) |arpeggio((((echo((arpeggio(echo(X,4,6) ) +transpose(transpose(X,-5) ,7) ) ,4,6) +transpose(step(transpose(echo(X,4,6) ,-7) ,12) ,7) ) +transpose((arpeggio(echo(shuffle((arpeggio(X) +shuffle(step(X,12) ) ) ) ,4,6) ) +((echo(transpose(X,-5) ,4,6) |transpose((transpose((X+transpose(X,7) ) ,-7) +(X+transpose(echo(X,4,6) ,7) ) ) ,-7) ) +arpeggio(step(shuffle(shuffle(X) ) ,12) ) ) ) ,4) ) +transpose((step(echo((transpose((X+transpose(X,12) ) ,-7) +transpose((shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) +step(X,12) ) ,7) ) ,4,6) ,12) +transpose((transpose((echo(step(X,12) ,4,6) |shuffle(arpeggio(X) ) ) ,4) |transpose(((echo(X,4,6) +transpose((((X|X) +transpose((X+X) ,12) ) +transpose(X,12) ) ,4) ) +transpose(echo(echo(arpeggio(X) ,4,6) ,4,6) ,7) ) ,4) ) ,7) ) ,7) ) ) ) ,4) +transpose((((step(shuffle((((transpose(echo(((echo(X,4,6) +transpose(step(transpose(X,-5) ,12) ,7) ) |(((X+transpose(X,12) ) +shuffle(X) ) +(transpose(X,-5) +transpose(X,7) ) ) ) ,4,6) ,-5) +(transpose(step(arpeggio((X|X) ) ,12) ,-7) |shuffle(X) ) ) +transpose(arpeggio(arpeggio(echo((X+X) ,4,6) ) ) ,4) ) +transpose(step(arpeggio(((transpose(transpose(X,-5) ,-5) +(arpeggio(X) |X) ) |((X+transpose(X,12) ) +echo(X,4,6) ) ) ) ,12) ,7) ) ) ,12) +transpose(((transpose((transpose(((echo(step(transpose(X,4) ,12) ,4,6) +transpose((echo(X,4,6) +(echo(X,4,6) |X) ) ,4) ) +transpose(arpeggio(X) ,7) ) ,-7) +transpose(shuffle((step(X,12) +step(X,12) ) ) ,12) ) ,-7) +transpose(echo(echo(transpose(((arpeggio(X) +arpeggio(transpose(X,4) ) ) +transpose(shuffle(X) ,7) ) ,-5) ,4,6) ,4,6) ,4) ) +transpose((transpose(transpose(arpeggio(transpose(arpeggio(X) ,-5) ) ,4) ,4) |step(transpose(transpose(shuffle((echo(((transpose(transpose(X,-5) ,-7) +transpose(transpose((X+transpose(X,7) ) ,-7) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4,6) |((transpose(X,4) +transpose((X+(X+transpose(X,12) ) ) ,4) ) +transpose((arpeggio(X) +transpose(X,7) ) ,7) ) ) ) ,-7) ,-5) ,12) ) ,7) ) ,7) ) |(transpose(echo(shuffle(step(step((X+transpose(X,12) ) ,12) ,12) ) ,4,6) ,-5) +step(((((shuffle((((X+transpose(X,12) ) +transpose(X,4) ) +transpose(X,7) ) ) |X) |echo((X+transpose(shuffle(X) ,7) ) ,4,6) ) +transpose(arpeggio(transpose(transpose(echo(step(shuffle(X) ,12) ,4,6) ,-5) ,-7) ) ,4) ) +transpose(step(step(arpeggio(transpose(X,-5) ) ,12) ,12) ,7) ) ,12) ) ) +transpose((transpose(step(transpose(echo(step(shuffle(step(X,12) ) ,12) ,4,6) ,-5) ,12) ,-7) +transpose(shuffle(step(((arpeggio(echo((echo(echo(step(X,12) ,4,6) ,4,6) +(shuffle((X|X) ) |shuffle(transpose(X,4) ) ) ) ,4,6) ) +transpose(((transpose(transpose(X,4) ,-7) +transpose(echo(shuffle(step((X+transpose(X,7) ) ,12) ) ,4,6) ,4) ) +transpose(shuffle((X+X) ) ,7) ) ,4) ) +transpose(step(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ,7) ) ,12) ) ,12) ) ,7) ) ,4) ) +transpose(echo(step(shuffle(transpose(echo(arpeggio(transpose(arpeggio((arpeggio((X|X) ) +transpose(echo(echo(X,4,6) ,4,6) ,12) ) ) ,-5) ) ,4,6) ,4) ) ,12) ,4,6) ,7) ) ,7) ) ,7) ) +transpose(echo(echo(echo(transpose(shuffle((transpose(transpose(shuffle(shuffle(transpose((transpose(shuffle((((X+transpose(X,7) ) +transpose((X|X) ,4) ) +transpose(X,7) ) ) ,-5) +arpeggio(X) ) ,-7) ) ) ,-5) ,-7) |(((((arpeggio(arpeggio(transpose(shuffle(transpose(X,4) ) ,4) ) ) +transpose((transpose(X,-7) +transpose(transpose(X,4) ,7) ) ,7) ) |(arpeggio(arpeggio(X) ) +step(X,12) ) ) +(step(shuffle(transpose((X+transpose(transpose(X,4) ,7) ) ,4) ) ,12) |(echo(transpose(X,-5) ,4,6) +transpose(step(arpeggio(shuffle(arpeggio(X) ) ) ,12) ,12) ) ) ) +transpose((shuffle((transpose(((transpose(X,4) +transpose(shuffle(X) ,12) ) +arpeggio(transpose(X,-5) ) ) ,4) +transpose(transpose((shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose((echo(X,4,6) +X) ,7) ) ,-5) ,12) ) ) +transpose(step(((step((transpose(X,-7) +echo(X,4,6) ) ,12) +transpose(shuffle(transpose(echo(X,4,6) ,-5) ) ,4) ) +transpose((echo(echo(X,4,6) ,4,6) |echo(arpeggio(X) ,4,6) ) ,7) ) ,12) ,12) ) ,4) ) +transpose(((arpeggio((X|X) ) +transpose(arpeggio((X+transpose(X,12) ) ) ,7) ) +transpose(transpose(transpose(shuffle((X+(X|X) ) ) ,-5) ,-5) ,7) ) ,7) ) ) ) ,-7) ,4,6) ,4,6) ,4,6) ,4) ) +transpose((arpeggio(((transpose((shuffle(transpose(transpose((((((shuffle(X) |(arpeggio(arpeggio(X) ) +transpose(X,4) ) ) +transpose(echo((((step(X,12) |transpose(X,-7) ) +transpose(transpose(step(X,12) ,-5) ,4) ) +transpose(shuffle((X+X) ) ,7) ) ,4,6) ,4) ) +transpose(arpeggio(echo(echo(step(X,12) ,4,6) ,4,6) ) ,7) ) +((echo((step(transpose(X,-7) ,12) +transpose((X+X) ,12) ) ,4,6) +transpose((transpose(X,4) +(transpose(transpose(X,-7) ,-5) +transpose(X,-7) ) ) ,12) ) +((X+transpose((X+X) ,7) ) +transpose((transpose(X,-5) +transpose(arpeggio(X) ,12) ) ,12) ) ) ) |(step(shuffle((step(arpeggio(X) ,12) +echo(X,4,6) ) ) ,12) |echo(arpeggio(arpeggio(X) ) ,4,6) ) ) ,4) ,-7) ) +((shuffle(step(step(echo(X,4,6) ,12) ,12) ) +transpose(echo(arpeggio(echo((step(shuffle(X) ,12) +arpeggio((X|X) ) ) ,4,6) ) ,4,6) ,4) ) +transpose(transpose(step(((arpeggio(shuffle(X) ) +transpose((((step(shuffle(X) ,12) |arpeggio(transpose(X,-5) ) ) +echo((X|X) ,4,6) ) +transpose(transpose(transpose(X,4) ,-7) ,7) ) ,4) ) +transpose(echo((shuffle(X) +transpose(step(X,12) ,7) ) ,4,6) ,7) ) ,12) ,-5) ,7) ) ) ,-7) +transpose(((shuffle(step(echo(echo((transpose(shuffle((X|transpose((X|X) ,4) ) ) ,-5) +step(transpose((shuffle((X|X) ) |transpose(transpose(X,4) ,4) ) ,-7) ,12) ) ,4,6) ,4,6) ,12) ) +transpose(transpose(step(transpose(echo(transpose(transpose(arpeggio(((((step(X,12) +transpose((X|X) ,4) ) +transpose(step(X,12) ,7) ) +transpose(transpose(X,-5) ,4) ) +transpose((echo(X,4,6) +transpose(transpose(X,4) ,12) ) ,7) ) ) ,-5) ,-5) ,4,6) ,-7) ,12) ,-7) ,4) ) +transpose((step(echo(shuffle((transpose(step(X,12) ,4) |arpeggio(step((X|(X|X) ) ,12) ) ) ) ,4,6) ,12) +echo(arpeggio(arpeggio((transpose(transpose(echo(X,4,6) ,-5) ,4) +transpose((step(step(echo(X,4,6) ,12) ,12) +transpose(((echo(arpeggio(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,4,6) +((transpose(X,-5) +transpose(X,-5) ) +transpose(step(step(((X|X) +transpose(X,-7) ) ,12) ,12) ,12) ) ) +transpose(transpose((step((X+X) ,12) |transpose(transpose(X,-7) ,-7) ) ,-7) ,7) ) ,12) ) ,12) ) ) ) ,4,6) ) ,7) ) ,4) ) +transpose(((echo((((echo(arpeggio((echo(transpose(((X|X) +transpose(step(X,12) ,12) ) ,-7) ,4,6) +arpeggio(((X+X) +transpose(((arpeggio(X) +transpose(X,4) ) +transpose(arpeggio(X) ,7) ) ,12) ) ) ) ) ,4,6) +(echo(((transpose(step(X,12) ,-5) +transpose(step(X,12) ,-5) ) +transpose(step(transpose(X,4) ,12) ,7) ) ,4,6) +((shuffle(transpose(arpeggio((((echo(X,4,6) +transpose(X,4) ) +transpose(shuffle(X) ,7) ) +(step(X,12) |X) ) ) ,-7) ) +transpose(transpose(step(echo(echo(arpeggio(X) ,4,6) ,4,6) ,12) ,4) ,4) ) +transpose(arpeggio((((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) +(X|X) ) +transpose(((X+X) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ) +transpose(shuffle(transpose((X|(X+X) ) ,-5) ) ,7) ) ) ,7) ) ) ) +transpose(echo(transpose(arpeggio(arpeggio(shuffle(echo(transpose((echo(X,4,6) |(X+X) ) ,-5) ,4,6) ) ) ) ,4) ,4,6) ,4) ) +transpose(transpose((step(echo(arpeggio(step(X,12) ) ,4,6) ,12) +transpose(step(arpeggio((shuffle((((X+transpose(X,12) ) +transpose(X,4) ) +transpose(X,7) ) ) |echo(transpose(X,-7) ,4,6) ) ) ,12) ,12) ) ,-5) ,7) ) ,4,6) +transpose(((transpose(shuffle(transpose(((transpose(X,4) +transpose(((transpose(X,4) +transpose(X,7) ) +transpose(X,12) ) ,4) ) +transpose((shuffle(X) +transpose((((X+transpose((X+transpose(X,12) ) ,4) ) +transpose((X|X) ,7) ) |transpose(echo(X,4,6) ,-7) ) ,12) ) ,7) ) ,-5) ) ,4) |arpeggio(arpeggio((echo(transpose(((arpeggio(((transpose(X,-7) +transpose((X|X) ,7) ) |transpose(X,-5) ) ) +transpose(transpose(X,-5) ,4) ) +transpose(((transpose(X,4) +transpose(transpose(X,4) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ,7) ) ,-7) ,4,6) |transpose(shuffle(step(((transpose(X,4) |(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(arpeggio(X) ,12) ) ) |transpose(shuffle(X) ,-5) ) ,12) ) ,-7) ) ) ) ) +echo(echo((shuffle(shuffle(transpose((echo(((transpose(arpeggio(X) ,4) +transpose(step(transpose((X|transpose(X,-7) ) ,-5) ,12) ,7) ) +((X+X) +X) ) ,4,6) +step((arpeggio(echo(X,4,6) ) +transpose((transpose(X,4) +transpose(arpeggio(((X|X) |(X+X) ) ) ,12) ) ,7) ) ,12) ) ,-5) ) ) +transpose((shuffle(((transpose(X,4) |(arpeggio(X) +transpose(transpose(X,4) ,-5) ) ) +transpose(((X|step(X,12) ) |shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,-7) ) ) |transpose(((echo(arpeggio(((echo(X,4,6) +transpose(echo(X,4,6) ,4) ) +transpose(shuffle(X) ,7) ) ) ,4,6) +transpose(echo(X,4,6) ,7) ) +shuffle(shuffle((X+transpose(step(shuffle(X) ,12) ,12) ) ) ) ) ,-7) ) ,7) ) ,4,6) ,4,6) ) ,4) ) +transpose(step((((echo((((arpeggio(step((echo((X+transpose(X,12) ) ,4,6) +transpose(arpeggio((step(X,12) +X) ) ,7) ) ,12) ) +transpose((transpose(arpeggio(((transpose(X,-5) +transpose(transpose(echo(X,4,6) ,-7) ,4) ) +transpose((((X+transpose(X,12) ) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ) ,-7) +transpose((arpeggio(((shuffle(X) +transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) ) +transpose((echo(X,4,6) +step((arpeggio((X+transpose(X,12) ) ) +transpose(X,7) ) ,12) ) ,7) ) ,12) ) ,12) ) +transpose((shuffle((transpose(((shuffle(X) +transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ,-5) +arpeggio(arpeggio(arpeggio(X) ) ) ) ) |arpeggio(transpose((transpose((X+(((X+transpose(X,4) ) +transpose(X,7) ) +echo(X,4,6) ) ) ,-7) +transpose(echo(X,4,6) ,-5) ) ,-5) ) ) ,4) ) +transpose(echo(transpose((X+transpose(X,7) ) ,-5) ,4,6) ,7) ) ,4,6) +transpose(transpose(echo((arpeggio(transpose(X,-7) ) +transpose(transpose(transpose(step(X,12) ,-5) ,4) ,12) ) ,4,6) ,-7) ,12) ) +transpose(step(arpeggio((transpose((shuffle(arpeggio(echo(X,4,6) ) ) +(transpose((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ,-5) |step(X,12) ) ) ,-5) +transpose(((shuffle(step((echo(X,4,6) +transpose((X+transpose(X,12) ) ,12) ) ,12) ) +shuffle((X+transpose(transpose(X,-5) ,12) ) ) ) |(((transpose(X,-7) +transpose(X,12) ) +transpose(transpose(echo(transpose(echo(X,4,6) ,4) ,4,6) ,-5) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ) ,12) ) ) ,12) ,4) ) +transpose(step(arpeggio(shuffle(step((arpeggio(echo(transpose(echo(X,4,6) ,-5) ,4,6) ) |((shuffle(arpeggio(transpose((X+X) ,-7) ) ) |echo(arpeggio(step(X,12) ) ,4,6) ) +transpose(((X|X) |step(echo(transpose(arpeggio(X) ,-7) ,4,6) ,12) ) ,12) ) ) ,12) ) ) ,12) ,7) ) ,12) ,7) ) ,7) ) ) +step(((((arpeggio(((shuffle(shuffle((shuffle((X+transpose((X+transpose(X,7) ) ,12) ) ) +transpose((X+transpose(X,12) ) ,7) ) ) ) +transpose(step(echo(((shuffle(transpose(((step(X,12) |echo(X,4,6) ) +transpose(shuffle(transpose(X,-5) ) ,12) ) ,4) ) +transpose((((echo(transpose(X,-7) ,4,6) +echo(X,4,6) ) +echo(((X+X) |arpeggio(X) ) ,4,6) ) +transpose((transpose(transpose(shuffle(X) ,4) ,-7) +transpose((echo(X,4,6) +transpose((X+X) ,12) ) ,12) ) ,7) ) ,4) ) +transpose((transpose(echo(echo((arpeggio(X) +echo(X,4,6) ) ,4,6) ,4,6) ,-7) +shuffle(step(X,12) ) ) ,7) ) ,4,6) ,12) ,4) ) +transpose(echo((transpose(shuffle(step(shuffle(X) ,12) ) ,-7) +transpose((step(((shuffle(X) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) +echo(shuffle(X) ,4,6) ) ,12) ) ,4,6) ,7) ) ) +step(transpose(arpeggio(arpeggio(shuffle((arpeggio(echo(transpose(X,-5) ,4,6) ) +transpose(transpose(step(X,12) ,4) ,7) ) ) ) ) ,-7) ,12) ) +transpose(((transpose(((((arpeggio(((X|X) |((transpose(X,-7) +transpose((X+X) ,4) ) +transpose(X,7) ) ) ) +transpose((transpose(X,-5) +echo(arpeggio(X) ,4,6) ) ,4) ) +transpose(transpose(step(((step(X,12) +transpose(X,4) ) +transpose(shuffle(X) ,7) ) ,12) ,-5) ,7) ) +transpose(shuffle((step(X,12) +transpose(X,7) ) ) ,12) ) |transpose((((arpeggio(shuffle(X) ) +(X+transpose((X|X) ,7) ) ) +transpose(echo(arpeggio(arpeggio(X) ) ,4,6) ,4) ) +transpose(transpose(transpose(X,-5) ,4) ,7) ) ,4) ) ,-7) +transpose((((echo((((X+transpose(X,4) ) +transpose(X,7) ) +shuffle(X) ) ,4,6) +transpose(step(((X|X) |X) ,12) ,12) ) +arpeggio(step(shuffle(X) ,12) ) ) |((step((arpeggio(transpose(X,-7) ) +transpose(transpose((arpeggio(transpose((X+transpose(X,12) ) ,4) ) +transpose(step(X,12) ,7) ) ,-5) ,7) ) ,12) +transpose(step(echo(arpeggio((((X|X) +transpose((X|X) ,7) ) +transpose(transpose((X+transpose(X,7) ) ,-7) ,7) ) ) ,4,6) ,12) ,4) ) +transpose((shuffle(shuffle(shuffle(step(X,12) ) ) ) +transpose(((arpeggio(X) |echo(echo(X,4,6) ,4,6) ) |shuffle(transpose(((echo(echo(X,4,6) ,4,6) +transpose(arpeggio((X+transpose(X,7) ) ) ,4) ) +transpose(step(step(X,12) ,12) ,7) ) ,-7) ) ) ,12) ) ,7) ) ) ,12) ) +transpose(echo((transpose(echo(arpeggio(shuffle(((((X|X) +transpose(X,4) ) +transpose(arpeggio(X) ,7) ) +transpose(arpeggio(X) ,12) ) ) ) ,4,6) ,4) |transpose(transpose((shuffle(transpose(X,-5) ) +transpose(transpose(((arpeggio(transpose(X,4) ) +transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ,-5) ,7) ) ,4) ,-5) ) ,4,6) ,-7) ) ,12) ) +(shuffle(shuffle(((echo(transpose(transpose(arpeggio(echo(X,4,6) ) ,4) ,4) ,4,6) +transpose((step((echo(echo(X,4,6) ,4,6) +transpose(echo(((arpeggio(X) +transpose(arpeggio(X) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4,6) ,7) ) ,12) +transpose(shuffle(echo(step(X,12) ,4,6) ) ,-5) ) ,7) ) |arpeggio(echo(transpose(shuffle(((X+transpose(shuffle(X) ,4) ) +transpose(transpose(X,-7) ,7) ) ) ,4) ,4,6) ) ) ) ) |((step(shuffle((echo((X+transpose((X+(X+X) ) ,7) ) ,4,6) |echo((transpose(((echo(X,4,6) +transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) ,-7) +transpose(((arpeggio(X) +transpose(transpose(X,-7) ,12) ) +transpose(transpose(step(X,12) ,-5) ,7) ) ,12) ) ,4,6) ) ) ,12) +transpose((transpose((((((X+X) |transpose(X,4) ) +transpose(transpose(arpeggio(X) ,-5) ,12) ) +transpose(shuffle(step(transpose(arpeggio((X+X) ) ,4) ,12) ) ,4) ) +transpose((arpeggio((echo((X|X) ,4,6) +shuffle(X) ) ) +shuffle(((transpose(transpose((X+X) ,-5) ,-7) +transpose(transpose((X|X) ,-7) ,4) ) +transpose((step(X,12) +transpose(transpose(X,4) ,12) ) ,7) ) ) ) ,7) ) ,4) +step((transpose(shuffle(X) ,-7) |(transpose(shuffle(X) ,4) +transpose((arpeggio((X+transpose(X,12) ) ) |transpose((X|X) ,4) ) ,7) ) ) ,12) ) ,4) ) +transpose(((((step(step(transpose(X,-5) ,12) ,12) +transpose(step(X,12) ,4) ) |transpose(step(X,12) ,4) ) +transpose((transpose(((echo(echo(step(X,12) ,4,6) ,4,6) +(((((X+transpose(X,7) ) +transpose(transpose(X,-5) ,4) ) +transpose(shuffle(X) ,7) ) +((X|X) |echo(X,4,6) ) ) |transpose(transpose(X,-5) ,4) ) ) +((transpose(arpeggio(shuffle(X) ) ,-7) +transpose((shuffle(X) +X) ,12) ) +transpose(((((X+transpose(X,7) ) |(X+transpose(X,12) ) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,4) ,7) ) ,7) ) +transpose((X+transpose((X+transpose(X,12) ) ,12) ) ,7) ) ,7) ) ) ,-5) +((arpeggio(step(transpose(X,4) ,12) ) +transpose(transpose((arpeggio(step((X|X) ,12) ) +transpose(transpose((shuffle(X) |X) ,-5) ,12) ) ,4) ,7) ) +arpeggio(echo(transpose((((X|transpose(X,4) ) |echo(transpose(X,-7) ,4,6) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ,12) ) ,-7) ,4,6) ) ) ) ,4) ) +transpose((shuffle(arpeggio((((echo((step(X,12) |(X+transpose(X,12) ) ) ,4,6) +transpose((step(X,12) |arpeggio(X) ) ,12) ) +transpose(shuffle(step(transpose(X,-7) ,12) ) ,4) ) +transpose(step((X+arpeggio(X) ) ,12) ,7) ) ) ) +transpose(((step(transpose(echo(echo((echo(X,4,6) |X) ,4,6) ,4,6) ,4) ,12) +transpose(transpose(echo(transpose((step((transpose(X,-7) +transpose(X,4) ) ,12) +transpose(transpose(X,-5) ,4) ) ,-5) ,4,6) ,-5) ,4) ) +transpose(transpose(((echo(transpose(X,-5) ,4,6) |step(shuffle(X) ,12) ) +transpose(shuffle(transpose(X,-5) ) ,12) ) ,-5) ,7) ) ,7) ) ,7) ) ,7) ) ) ) +transpose(shuffle(arpeggio(((transpose(shuffle(transpose(transpose((echo(shuffle(echo((X+X) ,4,6) ) ,4,6) |(transpose((step(X,12) |shuffle(step(X,12) ) ) ,-5) |echo(step(shuffle(X) ,12) ,4,6) ) ) ,-5) ,-7) ) ,4) +transpose(arpeggio(transpose(shuffle((transpose(arpeggio(transpose(((((step(X,12) +transpose(step(X,12) ,4) ) +transpose(echo(X,4,6) ,7) ) +transpose(step(shuffle(X) ,12) ,4) ) +transpose((shuffle(X) +transpose((X|X) ,7) ) ,7) ) ,-5) ) ,-5) +transpose((transpose(X,-7) +transpose(X,4) ) ,7) ) ) ,-7) ) ,4) ) +transpose(echo(echo((arpeggio(step(arpeggio(transpose(transpose(arpeggio(X) ,4) ,-7) ) ,12) ) +transpose(echo(((step(transpose(X,-7) ,12) +transpose((X+transpose(arpeggio(X) ,7) ) ,12) ) |(transpose(X,4) +transpose(arpeggio(X) ,7) ) ) ,4,6) ,12) ) ,4,6) ,4,6) ,7) ) ) ) ,7) ) ,12) ) ,7) )
random seed used was 113160512

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