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((((((X+transpose(X,12) ) +(X+transpose(X,7) ) ) +((X+transpose(X,-7) ) |shuffle(X) ) ) +transpose(transpose((X+transpose(echo(X,4,6) ,12) ) ,-5) ,12) ) +transpose(shuffle((step(shuffle(((X|X) +X) ) ,12) |transpose(transpose(echo(transpose(X,-5) ,4,6) ,-5) ,4) ) ) ,12) ) ,-7) +transpose((echo(transpose(arpeggio(((echo(X,4,6) |X) +transpose(transpose(step(arpeggio(X) ,12) ,-7) ,7) ) ) ,-5) ,4,6) +transpose(transpose((arpeggio(step(X,12) ) +transpose((((X+transpose(X,7) ) +transpose((X+transpose((X+X) ,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ,-5) ,12) ) ,-5) ) +transpose(transpose((transpose(arpeggio(transpose(transpose(transpose(shuffle(((step((X+transpose(X,7) ) ,12) +transpose(transpose((X|X) ,4) ,12) ) |(((X+X) +transpose((X|X) ,4) ) +transpose(transpose(X,-5) ,7) ) ) ) ,-7) ,-5) ,4) ) ,-7) +transpose(step(echo((step((((shuffle(X) +transpose(step(echo((X+transpose(X,12) ) ,4,6) ,12) ,7) ) +transpose((shuffle((X|(X+transpose(X,7) ) ) ) +transpose(((X|(X+X) ) +transpose((X+transpose(X,7) ) ,-5) ) ,7) ) ,4) ) +transpose(transpose((((transpose(X,4) +transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(((X|X) +transpose(X,7) ) ,-5) ,7) ) ,4) ,7) ) ,12) +transpose(((transpose((shuffle(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ) +((X+transpose(X,7) ) +step((X+transpose((X+X) ,12) ) ,12) ) ) ,-7) +transpose((arpeggio(transpose(transpose(arpeggio(X) ,-5) ,-7) ) |transpose(((X+transpose(X,12) ) |transpose(X,4) ) ,4) ) ,4) ) +transpose(transpose(((arpeggio(shuffle(transpose(step(X,12) ,4) ) ) +transpose(echo(transpose(shuffle((transpose((X|X) ,4) +transpose(transpose(transpose(X,4) ,-7) ,7) ) ) ,4) ,4,6) ,4) ) +transpose(shuffle(transpose(transpose(transpose(arpeggio(transpose(X,-7) ) ,4) ,4) ,4) ) ,7) ) ,4) ,7) ) ,7) ) ,4,6) ,12) ,12) ) ,-7) ,12) )
random seed used was 1 EXPR = (((transpose(echo((((transpose(((echo(((X+transpose(X,12) ) |echo(X,4,6) ) ,4,6) |transpose(((X+transpose(X,7) ) +X) ,-7) ) +transpose(transpose(X,4) ,4) ) ,-5) +transpose(step(transpose(transpose((((X+transpose(X,7) ) +echo(X,4,6) ) +transpose((X|(X+transpose(X,12) ) ) ,12) ) ,4) ,4) ,12) ,7) ) +transpose(transpose(echo(((arpeggio(((transpose((X+X) ,-7) |transpose(X,-5) ) +transpose(X,12) ) ) +transpose(step(transpose(X,-5) ,12) ,4) ) +transpose((transpose(transpose((X+X) ,-7) ,-7) +transpose((((X+transpose(X,7) ) +X) +transpose(transpose((X+transpose(X,12) ) ,-5) ,7) ) ,4) ) ,7) ) ,4,6) ,-5) ,4) ) +transpose(transpose((((shuffle(X) +transpose((echo(X,4,6) +(transpose(X,4) +X) ) ,12) ) |(transpose(transpose((X|X) ,-7) ,4) +(X+transpose((X|X) ,12) ) ) ) +transpose(transpose(transpose(X,-7) ,4) ,-5) ) ,4) ,7) ) ,4,6) ,4) |(transpose(arpeggio(transpose((transpose(X,4) +transpose(((X+transpose(X,7) ) +transpose((X|X) ,7) ) ,12) ) ,4) ) ,-5) +transpose(((echo((step(X,12) +step(X,12) ) ,4,6) +transpose((((X+transpose(X,7) ) +((X|X) +(X+transpose(X,7) ) ) ) |echo(step((X|X) ,12) ,4,6) ) ,4) ) +transpose(transpose(transpose(transpose(X,-5) ,4) ,-7) ,7) ) ,12) ) ) |transpose(arpeggio(shuffle(((echo(transpose(((X|transpose(X,-5) ) +transpose(transpose(X,4) ,12) ) ,-5) ,4,6) +transpose(echo(step(transpose(arpeggio((X+shuffle(X) ) ) ,-7) ,12) ,4,6) ,7) ) +transpose(transpose((((((X+X) +transpose(transpose(X,-5) ,7) ) |transpose(transpose(X,-7) ,-7) ) +(transpose(X,-5) +((transpose(X,-7) +transpose(transpose(step(X,12) ,4) ,4) ) +transpose(arpeggio(transpose((X|X) ,4) ) ,7) ) ) ) |transpose(((transpose(X,-5) +transpose((X+transpose(X,7) ) ,12) ) |shuffle(transpose(transpose(X,4) ,-7) ) ) ,-5) ) ,-7) ,12) ) ) ) ,4) ) +((((echo((echo((transpose(transpose(echo(X,4,6) ,4) ,-5) +((X+transpose((((X+transpose(X,7) ) +(X+X) ) |transpose(X,-7) ) ,12) ) |((((transpose(X,4) +transpose((X|X) ,4) ) +transpose(transpose(transpose(X,-7) ,-5) ,7) ) +transpose(((X+transpose(shuffle(X) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ,4) ) +transpose((X+((X+transpose(X,7) ) +transpose((X|X) ,7) ) ) ,7) ) ) ) ,4,6) +transpose(transpose((step(transpose(transpose(arpeggio(X) ,4) ,4) ,12) +transpose((transpose(((transpose(X,-5) +transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) ,4) +transpose(transpose(X,-5) ,12) ) ,12) ) ,-7) ,-7) ) ,4,6) +transpose(transpose((((X+(X+transpose(X,12) ) ) +shuffle(X) ) |((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+transpose(X,12) ) ,12) ) |transpose(X,-7) ) ) ,-7) ,7) ) +((((transpose(transpose(((step(X,12) +transpose((X+X) ,12) ) +transpose(shuffle(X) ,7) ) ,-7) ,4) +step(X,12) ) +(transpose(arpeggio((X|((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,4) |transpose(X,4) ) ) +transpose((transpose(((arpeggio((X+transpose(X,7) ) ) +transpose((arpeggio(transpose((X+transpose(X,12) ) ,4) ) +(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) +transpose(shuffle(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) +transpose(arpeggio(X) ,7) ) ) ,12) ) ) ,4) ) +transpose(((transpose(((X|X) |X) ,4) +transpose((((transpose(X,4) +transpose((X+transpose(X,12) ) ,4) ) +transpose(X,7) ) +transpose(X,12) ) ,12) ) +transpose(arpeggio(step(((X+transpose(X,7) ) +transpose(X,7) ) ,12) ) ,7) ) ,7) ) ,4) +transpose(arpeggio(echo((((X+transpose(X,4) ) +transpose(X,7) ) |transpose(X,-7) ) ,4,6) ) ,4) ) ,4) ) +transpose(transpose((((echo(transpose((X+(((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X|X) ,12) ) ) ,-5) ,4,6) +transpose(transpose((transpose((X+X) ,4) |transpose(step(X,12) ,4) ) ,-7) ,4) ) +transpose((echo((X+transpose(transpose(X,-5) ,12) ) ,4,6) +transpose((((step(echo(X,4,6) ,12) +transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) +transpose((shuffle(X) +transpose(X,4) ) ,12) ) ,12) ) ,7) ) +(X+transpose((((X+transpose(X,4) ) +transpose(X,7) ) +(X+X) ) ,4) ) ) ,4) ,7) ) ) +transpose((echo(shuffle(arpeggio((echo((X+transpose(X,7) ) ,4,6) +transpose(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ) ) ) ,4,6) +transpose(transpose(((shuffle(step((X+X) ,12) ) +transpose((transpose(X,-5) +X) ,4) ) +((transpose(transpose(X,-5) ,-5) +transpose(echo(transpose(transpose(X,4) ,-7) ,4,6) ,7) ) +(transpose(X,-7) +transpose(((((X|((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(X,7) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) +transpose(transpose((arpeggio((X+X) ) |echo(X,4,6) ) ,-5) ,7) ) ,7) ) ) ) ,-7) ,12) ) ,4) ) +transpose(arpeggio(((step(transpose(transpose(echo(((X+transpose(X,7) ) +((((X|X) +transpose(X,-5) ) +transpose(echo(X,4,6) ,7) ) +(((X+transpose(X,7) ) |(X+X) ) |X) ) ) ,4,6) ,4) ,-5) ,12) +transpose(transpose(shuffle(shuffle((X+X) ) ) ,-5) ,4) ) +transpose(transpose((transpose((shuffle((arpeggio(X) |transpose(X,-5) ) ) +transpose((transpose((((X+transpose(X,12) ) +transpose((X|X) ,4) ) +transpose(transpose(X,-7) ,7) ) ,-7) +X) ,7) ) ,-7) |transpose(((X|transpose(transpose(X,4) ,4) ) +transpose(transpose(shuffle(X) ,-5) ,7) ) ,-7) ) ,-7) ,7) ) ) ,7) ) )
random seed used was 0 EXPR = (transpose(transpose(shuffle(echo(echo((transpose(X,-7) +transpose(transpose(X,-7) ,-5) ) ,4,6) ,4,6) ) ,-5) ,4) +(arpeggio((echo(X,4,6) +transpose((((X|X) +shuffle(step(X,12) ) ) +transpose(transpose((((X+transpose(X,7) ) +transpose((X+X) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4) ,12) ) ,12) ) ) +transpose((arpeggio((((X+X) +transpose(transpose(step(X,12) ,-5) ,4) ) +transpose(arpeggio(transpose((X+transpose(X,4) ) ,-5) ) ,7) ) ) +transpose((((echo(X,4,6) |(X|X) ) +transpose((arpeggio(transpose(X,4) ) +transpose(transpose(X,4) ,12) ) ,-5) ) +transpose(echo(shuffle(transpose((echo(X,4,6) +transpose(X,12) ) ,-5) ) ,4,6) ,7) ) ,-7) ) ,7) ) )
random seed used was 0 EXPR = ((transpose(echo((((arpeggio(step(transpose(transpose((((X+X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose((X|X) ,7) ) ,-5) ,4) ,12) ) |((transpose(arpeggio(X) ,-7) +transpose(arpeggio((X+transpose(X,-5) ) ) ,12) ) +transpose((((((X|X) +transpose((X+(X+transpose(X,7) ) ) ,12) ) +transpose(((X+transpose(X,12) ) +X) ,4) ) +transpose(transpose((X+transpose(X,12) ) ,-5) ,7) ) +transpose(((step(X,12) +transpose((X+X) ,7) ) +transpose(transpose((X|X) ,4) ,12) ) ,12) ) ,12) ) ) +transpose(step(((echo(transpose(X,-7) ,4,6) +transpose((transpose((X+X) ,-5) |(((X+X) +step(X,12) ) +transpose(transpose(arpeggio(X) ,4) ,7) ) ) ,12) ) +shuffle((transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,-7) |((transpose(X,-7) +transpose(step((X+transpose(X,12) ) ,12) ,4) ) +transpose((transpose(X,4) +transpose(step(X,12) ,12) ) ,7) ) ) ) ) ,12) ,7) ) +shuffle((shuffle(((echo(X,4,6) |transpose(echo(step(X,12) ,4,6) ,-5) ) +transpose((((transpose((X+transpose(X,7) ) ,-5) |transpose(echo(X,4,6) ,4) ) +transpose(((X|arpeggio(X) ) |transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ,4) ) +transpose(transpose(transpose(transpose(X,-5) ,4) ,-5) ,7) ) ,7) ) ) |(echo((transpose((X+transpose((X|X) ,7) ) ,-7) +transpose(transpose(transpose(X,-7) ,4) ,4) ) ,4,6) +transpose(((((transpose(X,-7) +transpose(transpose(X,-7) ,12) ) +((X|X) +X) ) +transpose((X|X) ,7) ) +transpose((X+X) ,7) ) ,7) ) ) ) ) ,4,6) ,4) +(((shuffle(transpose(transpose((((((X|(X+transpose(X,7) ) ) |arpeggio(X) ) +transpose((transpose(X,-5) |transpose(echo(X,4,6) ,-5) ) ,4) ) +transpose(transpose(transpose(X,-5) ,-5) ,7) ) +transpose((X+transpose(X,4) ) ,12) ) ,4) ,-7) ) +transpose((((((arpeggio(echo(X,4,6) ) +transpose((transpose(shuffle(X) ,4) +(transpose(X,-5) +step(X,12) ) ) ,12) ) +transpose(((((step(X,12) +transpose(((X|X) +(X|X) ) ,4) ) +transpose((X+X) ,7) ) |((X+X) +transpose(X,-7) ) ) |transpose((((X+transpose(step(X,12) ,4) ) +transpose(X,7) ) +transpose(X,-7) ) ,-7) ) ,4) ) +transpose((arpeggio(X) +transpose(((echo((X+X) ,4,6) +X) +transpose((X+X) ,12) ) ,7) ) ,7) ) |transpose(((step(X,12) +(X+transpose(X,7) ) ) +(echo(X,4,6) |X) ) ,-5) ) +transpose((shuffle(step((transpose(transpose(X,-7) ,-5) +transpose((((X+transpose(X,12) ) +transpose(X,12) ) +X) ,7) ) ,12) ) +transpose((echo(transpose(arpeggio(transpose(X,-7) ) ,-7) ,4,6) |(((X+transpose(X,7) ) +X) +transpose((transpose(X,-7) +transpose(X,7) ) ,7) ) ) ,7) ) ,7) ) ,12) ) +transpose(shuffle((transpose(step(step(shuffle(arpeggio(echo(X,4,6) ) ) ,12) ,12) ,-7) +transpose(transpose(((transpose(((X+transpose(X,4) ) +transpose((X+X) ,7) ) ,-5) +((transpose(transpose((X|X) ,4) ,-7) +transpose(((transpose(X,4) +X) +transpose(transpose(X,-5) ,7) ) ,4) ) +transpose((X+transpose(shuffle(X) ,7) ) ,7) ) ) +(((((X+transpose(X,7) ) |X) +transpose((transpose(X,-7) +X) ,12) ) +transpose(transpose(X,4) ,4) ) +transpose(step(X,12) ,7) ) ) ,-7) ,7) ) ) ,12) ) +transpose(arpeggio(transpose(transpose((transpose(step(shuffle(X) ,12) ,4) +(((((X+X) +transpose(transpose(X,-7) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) +transpose((((X+transpose(shuffle(X) ,7) ) +transpose(arpeggio(X) ,4) ) +transpose(transpose(X,-7) ,7) ) ,7) ) +(transpose(X,-5) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ) ,-7) ,-5) ) ,12) ) ) +(step(((shuffle(X) +(transpose((transpose(X,-7) |(transpose(step(X,12) ,-5) +((((X|X) +transpose(echo(X,4,6) ,12) ) +transpose((transpose(X,4) |((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ) +transpose((transpose(X,-7) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ) ) ,4) +transpose((((echo(X,4,6) +transpose((transpose((X|X) ,4) +transpose(X,12) ) ,12) ) +transpose((transpose(X,-5) +transpose((transpose(transpose(X,-5) ,4) |X) ,7) ) ,4) ) +transpose((step(step(X,12) ,12) +transpose((echo(X,4,6) +transpose(step(transpose(X,-7) ,12) ,7) ) ,7) ) ,7) ) ,12) ) ) +transpose((echo(transpose((step(shuffle((X+transpose(X,12) ) ) ,12) +(((X|(X+transpose(X,12) ) ) +transpose(transpose(X,-5) ,4) ) +step(transpose(transpose(X,-5) ,-5) ,12) ) ) ,-7) ,4,6) +transpose(((step(transpose(((echo((X+transpose(X,12) ) ,4,6) +transpose(X,7) ) |shuffle((X|X) ) ) ,4) ,12) +transpose(((transpose((X|X) ,4) +transpose((step(X,12) +shuffle(step(X,12) ) ) ,12) ) |echo(transpose((X+(transpose(X,4) +transpose(X,7) ) ) ,-5) ,4,6) ) ,4) ) +transpose(transpose(transpose(arpeggio((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ) ,-7) ,4) ,7) ) ,12) ) ,7) ) ,12) +transpose(((((((transpose((arpeggio(((transpose(X,4) +transpose(transpose(X,4) ,-5) ) +(X+X) ) ) +transpose((transpose(step(X,12) ,-7) +transpose(transpose(transpose(X,-7) ,-7) ,-7) ) ,12) ) ,-7) +transpose((((arpeggio(X) +transpose((X+transpose(transpose(X,-5) ,12) ) ,12) ) +transpose(echo(transpose(X,-5) ,4,6) ,12) ) +transpose(((echo(transpose(X,4) ,4,6) +transpose(arpeggio((echo(X,4,6) |echo(X,4,6) ) ) ,4) ) +transpose(echo(X,4,6) ,7) ) ,12) ) ,4) ) +transpose(transpose(transpose(echo(X,4,6) ,4) ,-7) ,7) ) +transpose(transpose(step(echo(shuffle((X+transpose((X+transpose(X,12) ) ,12) ) ) ,4,6) ,12) ,-5) ,12) ) +arpeggio(((step((X+transpose(X,12) ) ,12) |transpose(echo(X,4,6) ,-5) ) |(step(X,12) |(X+step(X,12) ) ) ) ) ) +transpose(((transpose(transpose(transpose((X|X) ,-5) ,-7) ,-5) +transpose(echo(transpose(transpose(echo(X,4,6) ,4) ,-7) ,4,6) ,7) ) +transpose((echo(transpose(transpose((X+transpose(X,12) ) ,-5) ,-7) ,4,6) |transpose(((((((X|X) |(X+X) ) +X) +(((X+transpose(shuffle(X) ,4) ) +transpose(X,7) ) +(X|X) ) ) +transpose(step(X,12) ,4) ) +transpose(transpose((transpose(X,-5) |transpose((X+transpose(X,12) ) ,4) ) ,-5) ,7) ) ,-5) ) ,12) ) ,12) ) +transpose(transpose((((transpose(arpeggio(transpose(transpose(X,-5) ,-7) ) ,-7) +transpose((transpose(((X+arpeggio(X) ) +transpose(transpose(transpose(X,4) ,-7) ,-5) ) ,-7) +((((X+X) +transpose(transpose(X,-7) ,-5) ) +transpose(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) +transpose(((transpose(transpose(X,-5) ,-5) +((X+transpose(X,7) ) |X) ) +((X|X) |((X|X) +transpose(shuffle(X) ,12) ) ) ) ,12) ) ) ,4) ) +transpose(step(transpose(step(transpose((transpose(transpose(X,-7) ,4) +transpose(transpose((X+transpose(X,7) ) ,4) ,12) ) ,-7) ,12) ,-5) ,12) ,7) ) |((transpose(((X+transpose(step(X,12) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,-7) |shuffle(((arpeggio(transpose((X|X) ,4) ) +transpose((transpose((X+transpose(X,7) ) ,-5) +transpose(((X+transpose(X,12) ) |transpose(X,4) ) ,7) ) ,4) ) +transpose(transpose(shuffle(transpose((((X|X) +transpose((X+X) ,4) ) +transpose(X,7) ) ,4) ) ,-5) ,7) ) ) ) |arpeggio(transpose((transpose(step(shuffle(X) ,12) ,-5) +echo((X+step((X|X) ,12) ) ,4,6) ) ,4) ) ) ) ,-5) ,12) ) ,12) ) )
random seed used was 0

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