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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# of Tracks:
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After 20 generations the expression "X" became this:
(transpose((transpose(echo(((((shuffle(transpose((transpose(transpose(transpose((transpose(X,-7) +shuffle(X) ) ,-5) ,4) ,4) +transpose((((X|((X|X) +transpose((X+X) ,12) ) ) +transpose(transpose(((((X+transpose(X,7) ) |(X+transpose(X,12) ) ) +transpose(step(shuffle(X) ,12) ,4) ) +transpose(transpose(echo(X,4,6) ,-7) ,7) ) ,-5) ,4) ) +transpose((X+X) ,7) ) ,12) ) ,-7) ) +transpose(transpose(transpose(step(transpose(transpose(transpose(transpose((echo(X,4,6) |(X|X) ) ,-7) ,4) ,4) ,4) ,12) ,4) ,4) ,12) ) +transpose(step((transpose(((((echo(echo(X,4,6) ,4,6) +arpeggio(((X+transpose(X,7) ) +transpose(transpose(X,-5) ,12) ) ) ) |transpose(X,-7) ) +transpose(echo(((shuffle(X) +transpose(X,4) ) +transpose(transpose(echo(arpeggio(X) ,4,6) ,4) ,7) ) ,4,6) ,7) ) +((transpose(transpose(transpose(X,-7) ,4) ,4) +(((X|X) |step(X,12) ) +arpeggio(X) ) ) |echo((shuffle(X) +((X+transpose(X,12) ) |X) ) ,4,6) ) ) ,-5) |transpose(transpose(transpose((X+transpose(X,7) ) ,4) ,-5) ,-5) ) ,12) ,4) ) +transpose(transpose((((echo((shuffle(transpose(X,-7) ) +transpose((shuffle(X) +transpose(transpose(X,-5) ,12) ) ,7) ) ,4,6) +transpose(transpose((X|X) ,-5) ,12) ) +transpose((transpose(((transpose(X,-7) +transpose(transpose(X,-5) ,12) ) +transpose((arpeggio(X) +transpose(((X+transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ,7) ) ,4) +transpose(arpeggio(((step(arpeggio(X) ,12) +transpose((shuffle(step((X+transpose(X,7) ) ,12) ) +transpose(transpose(step(X,12) ,-7) ,7) ) ,4) ) +transpose(((transpose(X,4) +transpose(echo(X,4,6) ,7) ) +transpose((X+transpose(X,12) ) ,-5) ) ,7) ) ) ,7) ) ,12) ) |arpeggio(step(transpose((step(X,12) +transpose(transpose(X,-5) ,12) ) ,-5) ,12) ) ) ,-5) ,7) ) +echo((((((X|transpose(X,-7) ) +arpeggio(transpose(transpose(X,4) ,4) ) ) +transpose(step(((X|X) +arpeggio(X) ) ,12) ,7) ) |((transpose(transpose(X,-5) ,4) |step(((shuffle(X) +transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) ,12) ) +((transpose(X,-5) +transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) ) ) +(((transpose(transpose(transpose(shuffle((X|transpose((X+transpose(X,12) ) ,-5) ) ) ,4) ,-7) ,4) |arpeggio((echo((echo(X,4,6) |transpose(step(X,12) ,-5) ) ,4,6) +shuffle((shuffle(X) +transpose(X,7) ) ) ) ) ) +transpose(arpeggio(((((X+X) |(((X+X) +transpose((transpose(X,-5) +transpose((X+X) ,7) ) ,12) ) +transpose((X|X) ,-5) ) ) |transpose(echo(transpose(((transpose(X,4) +transpose((X+transpose(X,12) ) ,7) ) +(echo(X,4,6) +transpose(X,4) ) ) ,-7) ,4,6) ,-5) ) +transpose((transpose(transpose((X+X) ,-7) ,4) +transpose(step(arpeggio(X) ,12) ,12) ) ,7) ) ) ,4) ) +transpose(echo(transpose(step(shuffle(X) ,12) ,-5) ,4,6) ,7) ) ) ,4,6) ) ,4,6) ,4) +transpose(transpose(((arpeggio(shuffle(transpose((transpose(shuffle(shuffle(X) ) ,-5) |((transpose(X,-5) +transpose(X,4) ) |(transpose((X+transpose(X,12) ) ,4) +transpose(echo(X,4,6) ,7) ) ) ) ,4) ) ) |((transpose(arpeggio(transpose((((X+arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ) +transpose((X+X) ,4) ) +transpose((transpose(X,4) |(arpeggio(X) |X) ) ,7) ) ,4) ) ,-7) +transpose((transpose(arpeggio(((transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,4) +transpose(((transpose(X,4) +echo(shuffle(X) ,4,6) ) |(X|transpose(X,4) ) ) ,7) ) +transpose(transpose((transpose((X+transpose(X,12) ) ,-7) |X) ,4) ,4) ) ) ,-7) |(transpose(((shuffle(transpose(X,4) ) +transpose(((X|X) +transpose(arpeggio(X) ,12) ) ,12) ) |((transpose((X|X) ,-5) |(X+transpose(X,7) ) ) +transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ) ,-5) +transpose(step(transpose((((X+X) +echo(X,4,6) ) +transpose(transpose(transpose(X,-5) ,4) ,7) ) ,-5) ,12) ,7) ) ) ,12) ) +transpose(transpose(arpeggio(transpose((step(transpose(X,-5) ,12) +step(shuffle((X+(X|X) ) ) ,12) ) ,-5) ) ,4) ,12) ) ) +((arpeggio(transpose((step(shuffle(arpeggio(X) ) ,12) +X) ,-5) ) +transpose((echo(arpeggio(transpose(X,4) ) ,4,6) +transpose(transpose(transpose(transpose((X+X) ,-5) ,-5) ,-7) ,7) ) ,12) ) +transpose(((transpose(((echo(transpose(transpose(echo(transpose(X,-7) ,4,6) ,-5) ,4) ,4,6) |transpose(shuffle(transpose(shuffle((X+transpose(X,12) ) ) ,4) ) ,4) ) +transpose((echo((((X+transpose((X|X) ,4) ) +transpose(echo(X,4,6) ,7) ) |(echo(transpose(X,-7) ,4,6) +transpose(transpose(X,-5) ,7) ) ) ,4,6) |echo(transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) +transpose(transpose(X,4) ,7) ) ,4) ,4,6) ) ,4) ) ,4) +transpose(transpose(((((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose(arpeggio(X) ,7) ) |echo(((echo(X,4,6) +transpose(X,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,4,6) ) ,-5) ,12) ) +transpose(step(transpose(((transpose(transpose(transpose(X,-7) ,4) ,-7) +transpose(transpose(arpeggio(((echo(X,4,6) +transpose(X,7) ) +arpeggio(shuffle(transpose(X,4) ) ) ) ) ,-5) ,4) ) +transpose((((X+X) |X) |((X|X) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,7) ) ,-7) ,12) ,-5) ) ,7) ) ) ,-5) ,12) ) ,4) |arpeggio(echo((step(((echo(echo(((transpose(X,-7) +transpose(transpose(((X|X) +transpose(X,7) ) ,4) ,12) ) +(((X+echo(transpose(transpose(X,-5) ,-5) ,4,6) ) +transpose(step(transpose(X,-7) ,12) ,4) ) +transpose((X+transpose(transpose(X,-7) ,7) ) ,7) ) ) ,4,6) ,4,6) +transpose((transpose((((((((step(X,12) +transpose(echo((X|X) ,4,6) ,4) ) +transpose(shuffle((transpose(X,4) +transpose(X,12) ) ) ,7) ) +(echo(transpose(X,4) ,4,6) +(X+arpeggio(step(X,12) ) ) ) ) |arpeggio((((transpose(X,4) |shuffle(X) ) +transpose(step((X+X) ,12) ,4) ) +transpose(shuffle(shuffle(X) ) ,7) ) ) ) +transpose((transpose(echo((X|(X+X) ) ,4,6) ,4) +transpose(transpose(transpose((X+X) ,-7) ,-5) ,12) ) ,4) ) +transpose(shuffle(echo(transpose(transpose(((step(X,12) +transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+X) ,7) ) ,-5) ,12) ) +transpose(shuffle(X) ,4) ) ,-7) ,4) ,4,6) ) ,7) ) +transpose(((transpose(echo((echo((X+(X+X) ) ,4,6) +X) ,4,6) ,4) +(transpose(transpose(arpeggio(((transpose(X,-5) +transpose(shuffle(X) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,-5) ,4) +(transpose(transpose(transpose(X,-5) ,-7) ,4) +transpose(step(transpose((transpose(X,-7) |X) ,4) ,12) ,7) ) ) ) +shuffle(transpose(transpose(X,4) ,-5) ) ) ,7) ) ,4) +transpose(transpose(step(arpeggio(transpose(echo(transpose(transpose(transpose(transpose(X,4) ,-5) ,4) ,4) ,4,6) ,-7) ) ,12) ,-5) ,12) ) ,4) ) +transpose((((transpose(((transpose(((step(X,12) +echo((X|X) ,4,6) ) +transpose(echo(transpose(X,-5) ,4,6) ,12) ) ,4) +transpose(((transpose(X,4) |X) |(X+(X+transpose(X,12) ) ) ) ,12) ) +transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((arpeggio(X) +echo(X,4,6) ) ,-5) ) ,4) ,12) ) ,-5) +transpose((shuffle(transpose(transpose(arpeggio(transpose((X|X) ,4) ) ,-7) ,-7) ) +transpose((transpose(shuffle((X|transpose((X+X) ,4) ) ) ,4) |transpose(transpose(((((((X+transpose(X,12) ) +X) +transpose(X,12) ) +transpose(arpeggio(X) ,4) ) +transpose(transpose(transpose((X+X) ,-7) ,-7) ,7) ) |((X+transpose(X,12) ) |(X+X) ) ) ,-7) ,-5) ) ,7) ) ,12) ) +transpose((transpose(((((X|transpose(((X+transpose((X+transpose(X,12) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,7) ) ,-7) ) +(echo((X+X) ,4,6) |((transpose((X+X) ,-7) |transpose(transpose(X,-5) ,4) ) +transpose(((transpose(X,-7) +transpose(transpose(X,4) ,12) ) +echo(X,4,6) ) ,7) ) ) ) +transpose(step(transpose(shuffle(((X+transpose((X+transpose(X,12) ) ,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ) ) ,-7) ,12) ,7) ) +transpose(((transpose(transpose((X+X) ,4) ,-7) +transpose(shuffle(((transpose(arpeggio(transpose(X,-5) ) ,-5) +transpose(echo(X,4,6) ,12) ) |shuffle((transpose(arpeggio(X) ,-5) |((X+transpose(echo(transpose(X,-7) ,4,6) ,4) ) +transpose(X,7) ) ) ) ) ) ,12) ) |((arpeggio(((step(transpose(X,4) ,12) +transpose((echo((transpose(X,-7) |X) ,4,6) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) ,12) ) ,4) ) +transpose(transpose(shuffle(transpose(shuffle(X) ,4) ) ,4) ,7) ) ) +transpose(((transpose(X,-5) +transpose(transpose((X|echo(X,4,6) ) ,-5) ,7) ) |echo((transpose(transpose(X,-5) ,4) +transpose((X+transpose(X,-5) ) ,12) ) ,4,6) ) ,4) ) +transpose(echo(transpose((transpose(X,-7) +transpose(((X+transpose(X,12) ) +transpose(X,7) ) ,12) ) ,-7) ,4,6) ,7) ) ) ,7) ) ,-7) +transpose(transpose((transpose(((((X+transpose(transpose((X+transpose(X,12) ) ,-7) ,7) ) +transpose((transpose(X,-7) +shuffle(X) ) ,4) ) +transpose(transpose((X|X) ,4) ,7) ) +transpose(shuffle(X) ,7) ) ,-5) |(((transpose(transpose((X+X) ,-5) ,-5) +(step(((X+transpose(X,12) ) +transpose(step(X,12) ,7) ) ,12) |transpose((step((X+X) ,12) |shuffle(X) ) ,4) ) ) +transpose(((X+transpose((X|X) ,12) ) |transpose(X,-5) ) ,4) ) +transpose((((transpose((transpose(X,-7) +echo(X,4,6) ) ,4) +transpose(transpose(((X+transpose((X|X) ,4) ) +transpose(transpose(X,-5) ,7) ) ,4) ,12) ) +transpose(((arpeggio(X) +X) |transpose(echo(X,4,6) ,-7) ) ,4) ) +transpose(((X+(X|X) ) +((transpose(X,-7) +transpose(X,4) ) +transpose(step(X,12) ,7) ) ) ,7) ) ,7) ) ) ,-5) ,7) ) ,4) ) +transpose(transpose(((arpeggio(transpose(echo(X,4,6) ,4) ) +arpeggio(step(X,12) ) ) +transpose(((transpose(transpose(X,4) ,-7) +transpose(transpose(X,-7) ,12) ) |shuffle(echo(X,4,6) ) ) ,-5) ) ,4) ,7) ) ,7) ) ,12) |arpeggio(transpose((shuffle((transpose((step(transpose(shuffle(X) ,-5) ,12) +transpose(((((echo(X,4,6) +transpose(step(X,12) ,-5) ) +transpose(((X|X) +transpose(X,4) ) ,4) ) +transpose(((X|X) +transpose((X+transpose(X,7) ) ,7) ) ,7) ) +transpose((echo((arpeggio(X) +transpose(X,12) ) ,4,6) |transpose(shuffle(step(X,12) ) ,4) ) ,12) ) ,12) ) ,4) +transpose(echo((arpeggio(transpose(X,4) ) +transpose((arpeggio(((transpose(X,-7) |X) +transpose((((X|X) +transpose(echo(X,4,6) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,12) ) ) +transpose(shuffle(X) ,-5) ) ,12) ) ,4,6) ,12) ) ) +transpose((((((transpose((arpeggio(X) |X) ,4) |(transpose((X+X) ,-7) |arpeggio((X+X) ) ) ) +((X+transpose(arpeggio(transpose(X,4) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ) +transpose((transpose(transpose(transpose((X|X) ,-5) ,4) ,-5) |transpose((echo(X,4,6) +X) ,-5) ) ,12) ) |echo(((shuffle(X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,4,6) ) |((shuffle(transpose(transpose((X+transpose(X,7) ) ,-5) ,-7) ) +transpose(shuffle((X|(X+X) ) ) ,-5) ) +transpose(transpose((arpeggio(step(X,12) ) |arpeggio(transpose(X,-5) ) ) ,-7) ,4) ) ) ,4) ) ,-7) ) ) ,4,6) ) )
random seed used was 233324545

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