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 20 generations the expression "X" became this:
(((echo((((((((shuffle(transpose(arpeggio(X) ,-5) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) +((X+transpose((X+transpose(X,12) ) ,7) ) +transpose(step(shuffle((X+X) ) ,12) ,7) ) ) +transpose(((transpose(((((X+X) +transpose(transpose(X,4) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) |((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(arpeggio(X) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,-7) +shuffle(transpose((X+transpose(X,12) ) ,-7) ) ) |transpose(shuffle(step(X,12) ) ,-5) ) ,4) ) +transpose((((X+transpose(transpose(echo(transpose(X,-5) ,4,6) ,-7) ,4) ) +transpose(((step(transpose(X,-5) ,12) +transpose(step(shuffle(X) ,12) ,4) ) +transpose(transpose(((transpose(X,4) +transpose(X,4) ) +transpose((X+X) ,7) ) ,-7) ,7) ) ,7) ) +(((shuffle(X) +transpose(X,4) ) +transpose(transpose(((((echo(X,4,6) |X) |transpose(X,-7) ) +transpose((((X+transpose(X,7) ) +transpose(transpose(X,-5) ,7) ) |transpose((X+transpose(X,7) ) ,-7) ) ,4) ) +transpose(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,4) ,7) ) ,4) ,-7) ) +transpose(shuffle(transpose(shuffle((X+transpose(X,12) ) ) ,-7) ) ,4) ) ) ,7) ) |transpose((transpose(transpose(X,-7) ,4) +X) ,-7) ) +transpose((echo(((transpose(X,-5) +transpose(echo(((X+transpose((X|X) ,4) ) +transpose(X,7) ) ,4,6) ,4) ) |(((transpose((X+transpose(X,-7) ) ,-5) +transpose((transpose((X|X) ,-7) +transpose(transpose(X,-7) ,7) ) ,4) ) +transpose(((transpose(X,-5) +(X+X) ) +X) ,7) ) |((transpose(X,4) +arpeggio(X) ) |transpose(X,-7) ) ) ) ,4,6) +transpose(transpose((((transpose(step(X,12) ,4) |(X+transpose(step(X,12) ,12) ) ) +transpose((shuffle((((transpose(X,4) +(X+X) ) +transpose(transpose(X,-7) ,4) ) +transpose(transpose(X,-7) ,12) ) ) |arpeggio((transpose(X,-5) +transpose(X,12) ) ) ) ,4) ) +transpose(transpose(((shuffle((X+transpose(X,12) ) ) +transpose((((X+transpose(X,12) ) +transpose(arpeggio(X) ,12) ) +transpose(X,-5) ) ,-7) ) +transpose(((((transpose(X,-5) +transpose(transpose(X,-5) ,-7) ) +transpose(echo((X+X) ,4,6) ,12) ) +transpose(transpose(transpose((X+transpose(X,12) ) ,-7) ,-5) ,4) ) +transpose(transpose(step(X,12) ,-7) ,7) ) ,12) ) ,4) ,7) ) ,-5) ,7) ) ,4) ) +transpose((transpose((step(arpeggio(X) ,12) +transpose((step(arpeggio(transpose(X,4) ) ,12) +transpose(((X|X) +transpose(((transpose(X,-5) +transpose((X+transpose(X,12) ) ,4) ) +transpose(X,7) ) ,7) ) ,7) ) ,12) ) ,-7) +transpose(transpose(transpose(X,-5) ,-5) ,7) ) ,7) ) ,4,6) +transpose((shuffle(shuffle(transpose(shuffle(X) ,-5) ) ) +transpose(arpeggio((transpose(X,4) +transpose(transpose((X+transpose(X,12) ) ,-7) ,7) ) ) ,7) ) ,-7) ) +transpose(transpose((arpeggio((transpose(shuffle(transpose((step(X,12) +((X+transpose(X,12) ) +(X+transpose(X,12) ) ) ) ,-5) ) ,-5) +transpose((((transpose(step((arpeggio(X) +transpose(step(X,12) ,12) ) ,12) ,4) |(((X+transpose(X,7) ) +X) +transpose(X,7) ) ) +transpose(transpose(transpose(transpose(X,-7) ,-5) ,-5) ,4) ) +transpose(shuffle(step((transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(shuffle((X+X) ) ,12) ) ,4) |(arpeggio(echo(X,4,6) ) +transpose(((arpeggio(echo(X,4,6) ) +transpose(X,4) ) +transpose(transpose((X+transpose(X,7) ) ,-5) ,7) ) ,7) ) ) ,12) ) ,7) ) ,12) ) ) |(arpeggio(((transpose(X,4) +(X+transpose(X,12) ) ) +transpose(transpose((X|X) ,-7) ,7) ) ) |arpeggio(transpose((X|X) ,4) ) ) ) ,-7) ,7) ) |(((echo((transpose(((step(transpose(transpose(arpeggio(step(transpose(X,4) ,12) ) ,4) ,4) ,12) +step((step(step((X+X) ,12) ,12) +transpose(transpose((transpose(X,-5) +transpose((X+transpose(X,12) ) ,-7) ) ,-7) ,7) ) ,12) ) +(transpose(echo(((step(X,12) +transpose(X,4) ) +transpose((X|transpose(X,-5) ) ,7) ) ,4,6) ,-5) |transpose(transpose(transpose(transpose(X,-5) ,4) ,4) ,-5) ) ) ,-7) +transpose(echo(((((((echo((X+transpose(X,7) ) ,4,6) +transpose(transpose(arpeggio(X) ,4) ,4) ) +transpose(transpose(X,-7) ,7) ) +transpose((transpose(echo(X,4,6) ,-5) +transpose(echo(X,4,6) ,12) ) ,12) ) +transpose(((transpose(((X|X) +transpose(transpose(X,4) ,12) ) ,-5) +echo(shuffle(X) ,4,6) ) |transpose(transpose((X+transpose(X,12) ) ,-7) ,-7) ) ,12) ) +transpose((((echo(transpose(step((X+X) ,12) ,-7) ,4,6) +transpose(transpose((transpose((transpose(X,-7) +X) ,4) +transpose(transpose((X+transpose(X,12) ) ,4) ,7) ) ,4) ,4) ) +transpose(((X+X) +transpose(step(X,12) ,7) ) ,7) ) +transpose(transpose(shuffle((arpeggio(X) |(X+transpose((X+transpose(X,12) ) ,7) ) ) ) ,-7) ,12) ) ,7) ) +transpose(((transpose(X,-5) +transpose(transpose(shuffle(transpose(X,-5) ) ,-5) ,7) ) +transpose((((transpose(arpeggio(X) ,4) +transpose((X|(X+transpose(X,7) ) ) ,4) ) +transpose(transpose(transpose(X,4) ,-7) ,7) ) +transpose((((transpose(X,4) |X) +transpose((arpeggio((X|X) ) +((X+X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) ,12) ) +transpose(arpeggio(X) ,4) ) ,12) ) ,12) ) ,-7) ) ,4,6) ,12) ) ,4,6) +transpose(((transpose(((transpose(shuffle((((((shuffle(X) +transpose(shuffle((X+transpose(X,12) ) ) ,12) ) +transpose(transpose((((X+transpose((X+transpose(X,7) ) ,4) ) +transpose(X,7) ) |(X|X) ) ,-5) ,4) ) +transpose((((X+X) +X) +transpose(transpose(X,4) ,7) ) ,7) ) +transpose((((transpose(X,-7) +transpose(X,12) ) +transpose(step(X,12) ,4) ) |transpose((X+transpose(transpose(X,-5) ,12) ) ,-7) ) ,4) ) +transpose(((transpose(echo(transpose(X,-5) ,4,6) ,-5) +transpose((((transpose(transpose(X,-5) ,4) +transpose((X+X) ,4) ) +transpose(step((X+X) ,12) ,7) ) +transpose((X+transpose(X,12) ) ,4) ) ,4) ) +transpose((((X+transpose(X,7) ) |transpose((X|X) ,4) ) +shuffle((transpose(X,-5) +X) ) ) ,7) ) ,7) ) ) ,4) +transpose((arpeggio((echo(arpeggio(transpose(transpose(transpose(X,4) ,-7) ,4) ) ,4,6) +transpose((X+X) ,7) ) ) +transpose((step((arpeggio((X+((X+transpose(X,4) ) +transpose(X,7) ) ) ) +transpose(X,-7) ) ,12) +transpose(transpose(shuffle(arpeggio(transpose(X,-7) ) ) ,-7) ,7) ) ,12) ) ,4) ) +transpose(((((shuffle(X) +transpose(X,12) ) +transpose((transpose(X,-5) +transpose(transpose(X,4) ,12) ) ,12) ) +transpose((transpose(transpose(X,-5) ,-7) |transpose(shuffle(X) ,-5) ) ,4) ) |transpose(((((((((echo(X,4,6) +transpose(X,7) ) +transpose(transpose((X+X) ,4) ,4) ) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) +transpose((((transpose(X,4) +transpose(arpeggio(X) ,7) ) +transpose(transpose((transpose(X,4) |arpeggio(X) ) ,-5) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4) ) +transpose((((X+transpose(X,7) ) +transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,7) ) +transpose(transpose(transpose((X+X) ,-5) ,-5) ,4) ) +transpose(transpose(((X|X) +(X+transpose(X,12) ) ) ,-7) ,7) ) +transpose(transpose(transpose(transpose(arpeggio(X) ,-7) ,-5) ,-5) ,7) ) ,-7) ) ,7) ) ,4) +(transpose(((((((transpose(((X+transpose((transpose(X,-7) +transpose(echo(X,4,6) ,-5) ) ,4) ) +transpose((transpose(X,-7) +transpose(((transpose(X,4) +transpose(X,4) ) +transpose(X,7) ) ,12) ) ,7) ) ,-7) |transpose(echo(transpose(shuffle(transpose(X,4) ) ,-5) ,4,6) ,-5) ) |((((transpose(transpose(X,-5) ,-5) +transpose(echo(((X+transpose(X,12) ) +transpose(X,-5) ) ,4,6) ,7) ) +transpose(shuffle((X|(X+X) ) ) ,4) ) +transpose(((step(X,12) +X) +shuffle(X) ) ,7) ) |((((X+transpose(X,12) ) +transpose(X,12) ) |((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(X,7) ) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) ) ) +((shuffle(((transpose(X,4) +transpose((X+X) ,7) ) +transpose(transpose(X,-7) ,12) ) ) +transpose(((echo((X|X) ,4,6) +transpose((X+X) ,12) ) +transpose((((transpose(X,-7) |transpose(X,-5) ) +transpose(X,12) ) +transpose(transpose(X,4) ,12) ) ,7) ) ,4) ) +transpose(shuffle(shuffle(X) ) ,7) ) ) +transpose(transpose((step(transpose((X+transpose(X,12) ) ,4) ,12) +(((X+transpose(echo(X,4,6) ,12) ) +transpose(((X|X) +shuffle(X) ) ,4) ) +transpose(transpose(X,-7) ,7) ) ) ,4) ,4) ) +transpose((step((echo((transpose(((transpose(X,-7) +((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(X,12) ) ,4) |((((X|transpose(X,-7) ) +transpose((shuffle(X) |X) ,4) ) +transpose(X,7) ) +transpose(arpeggio(X) ,7) ) ) ,4,6) +transpose(arpeggio(echo(X,4,6) ) ,-5) ) ,12) |transpose(transpose(shuffle((transpose((X+X) ,-7) +((X+transpose(step(shuffle(X) ,12) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ) ) ,4) ,-5) ) ,4) ) +transpose(transpose(arpeggio((((((X+X) +transpose(arpeggio(transpose(X,-7) ) ,12) ) +transpose(((shuffle(X) +(X+transpose(step(X,12) ,12) ) ) +transpose(echo((X|X) ,4,6) ,-7) ) ,7) ) +transpose(transpose(shuffle((X|shuffle(X) ) ) ,-5) ,4) ) +transpose(((arpeggio(X) +transpose(transpose(X,-7) ,12) ) |transpose(step(X,12) ,-7) ) ,7) ) ) ,-5) ,7) ) ,-5) +transpose((transpose(((transpose((step(X,12) +(X+X) ) ,-7) +transpose((X|echo(transpose(X,4) ,4,6) ) ,7) ) +step((step((X+X) ,12) +transpose((X+X) ,7) ) ,12) ) ,4) |transpose(((step(transpose((arpeggio(step(X,12) ) +transpose(transpose(X,4) ,4) ) ,4) ,12) +(((X+transpose(transpose(X,4) ,7) ) +transpose(transpose(X,-5) ,7) ) +(transpose(echo(transpose(X,-5) ,4,6) ,-7) +transpose((transpose((X+X) ,4) +transpose((X+transpose(X,12) ) ,7) ) ,-5) ) ) ) +echo(((step(transpose(X,4) ,12) +transpose((transpose(X,-5) +transpose(X,-5) ) ,7) ) +((transpose((X|X) ,4) |((X+X) +transpose(((X+transpose(X,7) ) |X) ,7) ) ) +transpose(arpeggio(transpose(transpose(X,-7) ,-5) ) ,4) ) ) ,4,6) ) ,4) ) ,-5) ) ) +transpose(transpose(((transpose(step(step(transpose((((X+transpose(X,7) ) +transpose(X,7) ) |(X+transpose(X,7) ) ) ,4) ,12) ,12) ,4) +transpose(transpose((transpose(((((transpose(X,-5) +transpose((X+X) ,7) ) |(arpeggio(X) +transpose((X+transpose(X,12) ) ,7) ) ) +transpose(transpose(echo(transpose(X,-7) ,4,6) ,4) ,4) ) +transpose(X,7) ) ,-7) +transpose(transpose((echo(transpose((X+X) ,-5) ,4,6) +(echo(X,4,6) +((X|X) +(X+transpose(X,7) ) ) ) ) ,4) ,7) ) ,-5) ,4) ) +transpose(((transpose((arpeggio((transpose(X,-7) +transpose(transpose(X,-5) ,7) ) ) +(X|X) ) ,4) +transpose(transpose(transpose((((X+X) +transpose(arpeggio(X) ,12) ) +transpose(transpose(X,4) ,12) ) ,-7) ,-7) ,-5) ) +transpose((transpose(transpose(echo(X,4,6) ,-5) ,-7) |transpose(((X+X) |X) ,4) ) ,4) ) ,7) ) ,4) ,-5) ) ,4) ) +transpose((transpose((transpose(transpose((step((transpose((X|(X+X) ) ,-7) +transpose((((X+X) +transpose(arpeggio(X) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ,12) ) ,12) +((((transpose(X,-7) |transpose(X,-5) ) +transpose(X,7) ) |arpeggio(X) ) +transpose(transpose(transpose(X,-5) ,4) ,7) ) ) ,-7) ,4) +arpeggio(step(transpose(echo(((((X+X) +(X+transpose(X,12) ) ) +transpose(((((transpose(X,-7) +transpose(shuffle((X+transpose(X,7) ) ) ,4) ) +transpose((echo(X,4,6) +transpose(transpose(transpose(X,-5) ,4) ,12) ) ,7) ) +(transpose(X,4) +transpose(echo(transpose(X,4) ,4,6) ,12) ) ) +transpose(((transpose((X|transpose(X,-7) ) ,4) +transpose(arpeggio(X) ,-5) ) +(transpose(X,-5) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,12) ) ) ,7) ) ,12) ) +((step((((X+transpose(X,7) ) +transpose((X|X) ,4) ) +transpose((X|X) ,7) ) ,12) +transpose(echo(echo(shuffle(transpose(X,-5) ) ,4,6) ,4,6) ,4) ) +transpose(((echo((X|X) ,4,6) +transpose((X|transpose(transpose(X,-7) ,-5) ) ,4) ) +transpose(((((X+(X|X) ) +transpose(transpose(step(X,12) ,-7) ,12) ) +transpose(shuffle((transpose(X,-7) +transpose(echo(X,4,6) ,12) ) ) ,4) ) +transpose(((X+transpose(X,7) ) +transpose(X,-7) ) ,7) ) ,7) ) ,7) ) ) ,4,6) ,-7) ,12) ) ) ,-5) +transpose((((shuffle(((echo(transpose(transpose(((shuffle(X) +transpose(shuffle(X) ,4) ) +transpose(transpose(X,-7) ,7) ) ,-7) ,-7) ,4,6) +transpose(((transpose((X+X) ,-5) +transpose((transpose(X,-7) +transpose(transpose(X,-5) ,7) ) ,-7) ) +transpose(transpose(transpose(step(transpose(X,4) ,12) ,-7) ,-5) ,7) ) ,12) ) |((((transpose(transpose((X+transpose(X,7) ) ,4) ,-7) |step((transpose(X,-5) |X) ,12) ) +transpose((echo(((X|X) +X) ,4,6) |(X+transpose(X,7) ) ) ,7) ) +transpose(transpose(transpose((step((transpose(X,4) |(X+transpose(X,12) ) ) ,12) |(X+transpose(X,7) ) ) ,-7) ,4) ,4) ) +transpose(((arpeggio(transpose(((transpose(X,4) |transpose(X,-7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ,4) ) +transpose(echo(shuffle(transpose(X,-7) ) ,4,6) ,4) ) +transpose((((transpose(X,4) |X) +transpose(transpose(X,-7) ,4) ) +transpose(transpose(X,-7) ,7) ) ,7) ) ,7) ) ) ) +transpose((echo(((transpose(transpose(transpose(transpose(shuffle(X) ,-7) ,-5) ,-5) ,-7) +transpose(transpose(((echo(shuffle(transpose((transpose(step(X,12) ,-5) +transpose(step(echo(X,4,6) ,12) ,12) ) ,4) ) ,4,6) +transpose(((transpose(X,4) +transpose((X+X) ,12) ) +(X+transpose(X,12) ) ) ,4) ) +transpose(step((((X+transpose(X,7) ) +X) +transpose((transpose(transpose(X,-5) ,-7) +echo(X,4,6) ) ,7) ) ,12) ,7) ) ,-5) ,4) ) +transpose((transpose((step((arpeggio(X) +transpose((X+X) ,7) ) ,12) +step(step(transpose(X,-5) ,12) ,12) ) ,-7) +transpose(arpeggio(((X+transpose((X+X) ,7) ) +transpose((X+transpose(X,12) ) ,7) ) ) ,4) ) ,7) ) ,4,6) +transpose(transpose(((((arpeggio(transpose(((echo(X,4,6) |((X+transpose(X,4) ) +transpose(X,7) ) ) |((X+transpose(transpose(X,-5) ,4) ) +transpose((X|X) ,7) ) ) ,-7) ) +transpose(arpeggio((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+transpose(X,7) ) ,12) ) +transpose((transpose(X,-5) +(X+X) ) ,12) ) |arpeggio(transpose(X,4) ) ) ) ,4) ) +transpose(arpeggio((((X+transpose(X,12) ) |(X+X) ) +(X|X) ) ) ,7) ) +transpose(transpose(transpose(((transpose(X,4) +transpose(transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,-5) ,4) ) +transpose(transpose(transpose(X,-5) ,4) ,7) ) ,-5) ,-7) ,12) ) +transpose(step(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-5) ,12) ,7) ) ,4) ,7) ) ,7) ) +transpose(transpose(transpose(transpose(transpose(step(transpose(shuffle((X+X) ) ,4) ,12) ,-7) ,4) ,-5) ,4) ,12) ) |echo(((((transpose(transpose(transpose(transpose(X,-5) ,4) ,-7) ,-5) +step((transpose(transpose(X,4) ,-5) |transpose((echo(X,4,6) |echo(X,4,6) ) ,-5) ) ,12) ) +transpose(transpose(((arpeggio((transpose(step(X,12) ,4) +transpose(((X+(X+X) ) +transpose(((arpeggio(X) +transpose((X|X) ,4) ) +transpose(((transpose(X,4) +transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ,7) ) ,12) ) ,12) ) ) +transpose(arpeggio(((X|X) +X) ) ,7) ) +transpose(((((((X+transpose(X,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(X,7) ) +transpose((X+transpose(transpose(X,4) ,12) ) ,4) ) +transpose(((transpose((X+transpose(X,7) ) ,-5) +transpose(((X+transpose(X,12) ) +(X+X) ) ,12) ) +shuffle(X) ) ,7) ) +((step(echo(echo(transpose(X,-7) ,4,6) ,4,6) ,12) +transpose((shuffle(echo(X,4,6) ) +transpose(transpose((X+transpose(X,7) ) ,-7) ,7) ) ,7) ) +transpose(transpose(transpose(X,-7) ,-7) ,-7) ) ) ,4) ) ,4) ,12) ) +transpose((transpose(transpose(arpeggio(transpose(X,-5) ) ,-5) ,-7) |transpose(transpose((shuffle(echo(transpose(X,-5) ,4,6) ) +transpose(arpeggio(X) ,7) ) ,4) ,4) ) ,7) ) +step(((((((transpose(echo(X,4,6) ,-7) +transpose(transpose((X|X) ,-5) ,12) ) +transpose(transpose(transpose((X+transpose((X+(X+transpose(X,7) ) ) ,7) ) ,-7) ,-5) ,12) ) +transpose(transpose(step((transpose(X,4) +transpose((transpose(transpose(X,-5) ,4) +transpose(echo((X+X) ,4,6) ,7) ) ,7) ) ,12) ,-5) ,4) ) +transpose(((((((transpose(X,4) +(X+transpose(X,12) ) ) +(X|X) ) +transpose(X,-5) ) +transpose(transpose(transpose(shuffle(X) ,-5) ,-5) ,7) ) +transpose(transpose((transpose((((X+X) +transpose(step(X,12) ,4) ) +transpose(transpose(X,4) ,7) ) ,-5) +X) ,-5) ,4) ) +transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) +((arpeggio(X) +X) |transpose(X,-7) ) ) ,7) ) ,7) ) +transpose((transpose(X,4) +shuffle(arpeggio(echo(transpose(X,4) ,4,6) ) ) ) ,7) ) +((((transpose((shuffle(((X+transpose(X,7) ) +(X+transpose(X,12) ) ) ) +(X|X) ) ,-5) +(transpose(X,4) |(transpose(X,-5) +(X|X) ) ) ) +transpose((transpose(((X|X) |transpose(X,-5) ) ,4) +transpose(echo((step(X,12) +((X|X) |((X+transpose(X,4) ) +transpose((X+transpose(X,12) ) ,7) ) ) ) ,4,6) ,7) ) ,12) ) +transpose((transpose(X,-5) +transpose((X|X) ,7) ) ,4) ) +((((((step((X+transpose(X,7) ) ,12) +X) +transpose((((transpose(X,4) +transpose(step(X,12) ,12) ) +transpose(transpose(X,-7) ,4) ) +transpose(echo((X+X) ,4,6) ,7) ) ,4) ) +transpose(echo((transpose(X,4) |X) ,4,6) ,7) ) |transpose((X+transpose(X,12) ) ,4) ) +transpose(arpeggio(transpose(transpose((X+transpose(X,7) ) ,-5) ,4) ) ,12) ) +transpose(transpose((echo(X,4,6) +(X|(X+X) ) ) ,-7) ,-5) ) ) ) ,12) ) ,4,6) ) ,12) ) ,7) ) |(transpose(transpose((((shuffle(transpose(arpeggio(arpeggio(transpose((X+X) ,-5) ) ) ,-5) ) +transpose((shuffle(transpose((transpose(echo(X,4,6) ,-7) |echo(((X|((X+transpose(X,7) ) +X) ) +echo(X,4,6) ) ,4,6) ) ,-7) ) +echo(echo((((transpose(X,4) |((X+transpose(X,4) ) +transpose(X,7) ) ) |transpose((step(X,12) +transpose(((echo(X,4,6) +transpose(X,4) ) +transpose((X|X) ,7) ) ,7) ) ,4) ) +(shuffle(arpeggio(X) ) +transpose((((X+transpose(X,12) ) +transpose((X+transpose(X,7) ) ,7) ) +transpose(transpose((X+transpose(X,7) ) ,-5) ,12) ) ,12) ) ) ,4,6) ,4,6) ) ,12) ) +transpose(((echo((arpeggio(X) +(X+transpose(X,12) ) ) ,4,6) +transpose(((transpose(((((transpose(transpose(X,-7) ,4) +transpose(transpose(X,-5) ,7) ) +transpose(transpose(step(transpose(X,4) ,12) ,-5) ,12) ) +(((transpose(X,4) +transpose(((transpose(X,-7) +transpose(X,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,4) ) +transpose(transpose(echo(X,4,6) ,4) ,7) ) +X) ) +(echo((X+transpose(X,12) ) ,4,6) +transpose(((X|X) +step(X,12) ) ,7) ) ) ,4) +transpose(echo(echo(transpose((shuffle(transpose(X,-7) ) +(((transpose(X,-5) +transpose(transpose(X,-5) ,7) ) |(X+transpose(X,4) ) ) |X) ) ,-5) ,4,6) ,4,6) ,4) ) +transpose(((step(transpose(transpose((X+shuffle(X) ) ,4) ,-5) ,12) |(step(X,12) +transpose(transpose(X,-7) ,12) ) ) +transpose((((transpose(X,4) +transpose((shuffle(transpose(step(X,12) ,-7) ) |(shuffle(arpeggio(X) ) |shuffle((X+X) ) ) ) ,7) ) +echo((arpeggio(X) +transpose(X,12) ) ,4,6) ) +transpose((shuffle((transpose(X,4) +((transpose(X,-7) +transpose(transpose(X,-5) ,4) ) +transpose(transpose(X,-7) ,7) ) ) ) +(transpose(X,4) +transpose(transpose(step(X,12) ,-5) ,7) ) ) ,12) ) ,12) ) ,7) ) ,12) ) |shuffle(transpose(((step(X,12) |arpeggio(X) ) +transpose(transpose(step(transpose(X,4) ,12) ,4) ,7) ) ,-7) ) ) ,7) ) +transpose((((transpose(((((step(X,12) |(transpose(X,-5) |(((X+X) +transpose(shuffle(X) ,12) ) +transpose(transpose(X,-7) ,7) ) ) ) +(((X+transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,7) ) |(((X+transpose(X,12) ) +transpose(echo(X,4,6) ,4) ) +transpose(transpose(transpose(X,-5) ,-5) ,7) ) ) +transpose(transpose(transpose((X+transpose(X,7) ) ,4) ,4) ,7) ) ) +transpose(transpose(shuffle(((((X|shuffle(X) ) +((arpeggio(transpose(X,-7) ) +transpose(echo(step(X,12) ,4,6) ,4) ) +transpose(X,7) ) ) +transpose(shuffle(((X+transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) ) ,12) ) +transpose((transpose(X,4) +transpose((echo(X,4,6) |X) ,7) ) ,-5) ) ) ,4) ,12) ) +transpose((transpose((((arpeggio(X) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) |transpose(X,4) ) ,4) +transpose(transpose(echo(step(((((transpose(X,4) +transpose(X,7) ) +transpose(X,12) ) +transpose(transpose(transpose(X,-5) ,-5) ,4) ) +transpose((echo(X,4,6) +transpose((X|echo(X,4,6) ) ,7) ) ,7) ) ,12) ,4,6) ,-5) ,7) ) ,12) ) ,4) +transpose((transpose(((step(X,12) +transpose(X,4) ) +transpose((X+X) ,7) ) ,-5) +transpose(transpose((shuffle(arpeggio(X) ) |transpose(X,-7) ) ,4) ,4) ) ,4) ) +transpose(transpose((echo((((shuffle((arpeggio(X) +transpose(transpose(X,-5) ,12) ) ) +transpose(shuffle(transpose((X+transpose(X,7) ) ,4) ) ,4) ) +transpose(transpose((((X|X) +transpose(X,4) ) +transpose(X,7) ) ,4) ,7) ) |(echo(arpeggio(transpose(X,4) ) ,4,6) +((X+X) +transpose(transpose(X,-5) ,12) ) ) ) ,4,6) |echo((transpose(echo(((X|X) +transpose(X,7) ) ,4,6) ,-7) +echo(((transpose(X,4) +transpose((arpeggio(X) +transpose(X,-7) ) ,4) ) +transpose(X,7) ) ,4,6) ) ,4,6) ) ,-7) ,7) ) +transpose((echo((transpose((((X+transpose(X,12) ) +transpose(((X|X) +transpose(echo((X|X) ,4,6) ,7) ) ,7) ) +transpose(((X+transpose(X,12) ) +(X|X) ) ,4) ) ,-5) +transpose(((transpose(((X|X) |step(X,12) ) ,-7) +transpose(transpose((X|X) ,4) ,7) ) +echo((arpeggio(arpeggio((shuffle((X|X) ) +transpose(transpose(X,-7) ,12) ) ) ) +((transpose(X,-7) |(X+transpose(X,12) ) ) |step(X,12) ) ) ,4,6) ) ,7) ) ,4,6) |transpose(step(((shuffle(transpose(transpose((step((X+X) ,12) |(X+X) ) ,-5) ,4) ) |(arpeggio((X|echo((X|X) ,4,6) ) ) +(echo((X+X) ,4,6) |((X|X) +transpose(X,12) ) ) ) ) +((transpose((shuffle(transpose(X,4) ) |echo(X,4,6) ) ,-7) |transpose(transpose(X,-5) ,-5) ) +transpose(((X+transpose(((X+transpose(X,12) ) +step(X,12) ) ,7) ) |step(echo(transpose(X,-7) ,4,6) ,12) ) ,7) ) ) ,12) ,4) ) ,12) ) ,12) ) ,4) ,-5) |transpose((transpose((transpose(transpose((((step((echo(X,4,6) |X) ,12) +transpose(shuffle(transpose(X,-7) ) ,7) ) |(((X+transpose(X,12) ) +X) |X) ) +(X|transpose(((X+transpose(X,7) ) +transpose(transpose(X,-5) ,7) ) ,-7) ) ) ,-7) ,-5) +transpose(transpose(transpose(transpose((arpeggio(X) +transpose((transpose(echo(X,4,6) ,-7) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ,12) ) ,-5) ,-7) ,-5) ,12) ) ,-7) +transpose(((transpose(transpose(shuffle(((X|(X+transpose(X,12) ) ) +transpose(echo(shuffle(X) ,4,6) ,12) ) ) ,-5) ,-5) +transpose((transpose(((X+(transpose(transpose(transpose((X+transpose(X,7) ) ,4) ,-5) ,-5) +(((X+transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) +transpose((X+X) ,-7) ) ) ) +transpose((((((transpose((((X+transpose(X,12) ) +transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ,4) +transpose(X,-5) ) +transpose(((transpose((X|X) ,-7) +transpose(((X+transpose((X+X) ,4) ) +transpose(transpose(X,4) ,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) +transpose(transpose(((X+transpose(X,12) ) +transpose((((X+X) +transpose(X,7) ) +transpose(transpose(X,-5) ,12) ) ,12) ) ,-5) ,7) ) +transpose((echo(transpose(shuffle(X) ,-7) ,4,6) +(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) +transpose((X+(X|X) ) ,12) ) ) ,4) ) +transpose(step(transpose(step(X,12) ,4) ,12) ,7) ) ,12) ) ,-5) |(((X+X) +transpose(step(X,12) ,7) ) +transpose(transpose((X+transpose(X,7) ) ,4) ,7) ) ) ,7) ) +transpose(((transpose((((transpose((X|transpose(transpose(X,4) ,-5) ) ,4) +transpose(transpose((X+X) ,4) ,4) ) +transpose(X,7) ) +transpose(step((((X+transpose(transpose(X,-7) ,4) ) +transpose(transpose(X,-7) ,7) ) +((X+transpose(X,7) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +X) ,12) ) ) ,12) ,12) ) ,4) +transpose(echo(((shuffle(X) +transpose((X+transpose(X,-5) ) ,12) ) +transpose(((((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(step(X,12) ,7) ) +(transpose(X,-5) +X) ) +shuffle(arpeggio(X) ) ) ,12) ) ,4,6) ,4) ) +transpose((arpeggio(transpose((transpose(X,-7) +(transpose((X+transpose(X,7) ) ,-7) +(transpose(X,-7) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ) ,-7) ) +transpose(transpose(transpose(transpose((((X+X) +transpose(echo(X,4,6) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4) ,-7) ,-5) ,12) ) ,7) ) ,7) ) ,7) ) ,-5) ) ) )
random seed used was 218969141

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