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:
# of Tracks:
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After 20 generations the expression "X" became this:
(transpose((arpeggio((transpose(shuffle(((((arpeggio((transpose(X,4) |echo(X,4,6) ) ) +transpose((arpeggio((X+(X+transpose(X,12) ) ) ) +((((X+(X+transpose(X,12) ) ) |transpose(((X+transpose(X,7) ) +transpose(X,12) ) ,-7) ) +transpose(transpose(transpose(X,-7) ,4) ,4) ) +transpose(transpose((X|X) ,-5) ,7) ) ) ,12) ) |((arpeggio(transpose((step(X,12) +transpose((X+X) ,12) ) ,-5) ) |(echo(((step(X,12) +echo((X+transpose(X,12) ) ,4,6) ) |(shuffle(shuffle((X|X) ) ) +transpose(transpose(X,-5) ,7) ) ) ,4,6) +transpose((step(((step(X,12) +(X+X) ) +echo(transpose(X,-7) ,4,6) ) ,12) +((echo((X+transpose(transpose(X,-7) ,-7) ) ,4,6) +transpose(transpose((X+transpose((X+X) ,7) ) ,-5) ,4) ) +transpose(echo(X,4,6) ,7) ) ) ,12) ) ) +transpose((arpeggio(((X+X) |((X|X) |X) ) ) +(transpose(((((X+X) +(X|X) ) +transpose((transpose(X,-5) +X) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4) +transpose((((transpose(((X|X) |X) ,-5) +arpeggio((X+transpose(X,12) ) ) ) +transpose(shuffle(step(shuffle(X) ,12) ) ,12) ) +transpose(arpeggio(X) ,-7) ) ,7) ) ) ,12) ) ) +transpose(transpose(((((arpeggio(X) +transpose(X,12) ) +transpose((transpose(X,-5) +transpose(transpose(step(X,12) ,4) ,12) ) ,7) ) +(transpose((arpeggio(transpose(X,4) ) +transpose(transpose((X|X) ,-5) ,7) ) ,-7) +transpose(((X+transpose((X|X) ,4) ) +transpose(X,7) ) ,-5) ) ) |transpose(echo(transpose((((((X+transpose(X,4) ) +transpose(X,7) ) +X) +transpose(((((X+X) +transpose(transpose(X,-5) ,7) ) +(X+X) ) |echo(step(X,12) ,4,6) ) ,4) ) +transpose(((X|X) +transpose(transpose(shuffle((X+transpose(X,7) ) ) ,-5) ,12) ) ,7) ) ,-5) ,4,6) ,4) ) ,-7) ,4) ) +transpose(((((step(((X+transpose(transpose((X+X) ,4) ,4) ) +transpose(((X+transpose((X+transpose(X,12) ) ,4) ) +transpose((X+X) ,7) ) ,7) ) ,12) +transpose((transpose(step(X,12) ,4) +transpose((X|echo(X,4,6) ) ,-7) ) ,4) ) +transpose((transpose((X+transpose(X,7) ) ,4) +transpose(transpose(shuffle(transpose(X,-7) ) ,-5) ,12) ) ,7) ) +transpose((echo((((X|((X+transpose(X,4) ) +transpose(X,7) ) ) |(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) |((X+transpose(X,4) ) +transpose(X,7) ) ) +echo(X,4,6) ) ) +((shuffle(transpose(transpose(arpeggio(X) ,-7) ,-5) ) +transpose(transpose(transpose((X+X) ,-5) ,-7) ,4) ) +transpose(transpose(((transpose(X,-7) +transpose(X,4) ) +transpose(X,7) ) ,-7) ,7) ) ) ,4,6) +transpose(step(((transpose(X,4) +transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,12) ,4) ) ,12) ) |(((shuffle(((transpose(transpose(X,4) ,-5) +transpose((transpose(X,-7) +transpose(transpose(X,4) ,7) ) ,12) ) |((echo(arpeggio(X) ,4,6) +X) +transpose(transpose(X,4) ,7) ) ) ) |transpose((((((X+X) +transpose((X+X) ,7) ) +transpose((transpose((X|X) ,4) +transpose(((X+X) +transpose(X,7) ) ,12) ) ,12) ) +transpose(transpose(arpeggio(shuffle((X+transpose(X,12) ) ) ) ,-7) ,12) ) +transpose(transpose((((step(shuffle(X) ,12) |echo(X,4,6) ) +transpose(step(X,12) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-5) ,7) ) ,4) ) +transpose(transpose(transpose((((arpeggio((X|X) ) +transpose(((transpose((X+X) ,-5) +transpose((X|(X+transpose(X,7) ) ) ,4) ) +transpose((X+((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ,4) ) +transpose(step(transpose(arpeggio(X) ,-5) ,12) ,7) ) |(transpose(transpose(transpose(X,-5) ,4) ,-5) +((transpose(X,-5) +transpose(transpose(X,-7) ,7) ) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(shuffle(X) ,7) ) +transpose((X+X) ,7) ) ,12) ) ) ) ,4) ,-5) ,4) ) +transpose(arpeggio((step(echo(X,4,6) ,12) +transpose(X,7) ) ) ,7) ) ) ,7) ) ) ,4) +step(arpeggio((transpose((X+transpose(transpose(X,4) ,12) ) ,-7) +transpose(transpose(transpose(transpose((transpose((X+transpose(X,7) ) ,4) +(arpeggio(step(X,12) ) |transpose(X,-5) ) ) ,-7) ,-5) ,-7) ,7) ) ) ,12) ) ) |transpose(transpose((((step(((transpose((transpose(X,4) +transpose(transpose(transpose(echo((X+transpose(X,-7) ) ,4,6) ,-5) ,-5) ,4) ) ,-5) +transpose((((echo(transpose((((transpose(shuffle(X) ,4) |(X+transpose(X,7) ) ) +transpose(transpose(transpose(X,4) ,4) ,12) ) +(X+X) ) ,-7) ,4,6) |((transpose((transpose(step(transpose(X,4) ,12) ,-5) +arpeggio(X) ) ,-7) +(step(shuffle(X) ,12) +transpose(step(((X+transpose(X,7) ) |transpose(X,4) ) ,12) ,12) ) ) +(transpose(transpose((transpose(X,-5) +transpose(step(X,12) ,12) ) ,-5) ,-5) +transpose(((transpose(X,4) +transpose(((transpose(transpose(echo(X,4,6) ,-7) ,-7) +transpose(arpeggio((X+transpose(X,12) ) ) ,4) ) +transpose((arpeggio(X) +X) ,7) ) ,4) ) +transpose(transpose(step(X,12) ,-5) ,7) ) ,7) ) ) ) +transpose(transpose(shuffle(((X|X) |(X+transpose(X,12) ) ) ) ,-7) ,4) ) +transpose(step(shuffle(((X+transpose((transpose(X,4) +(X+transpose(X,7) ) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ) ,12) ,7) ) ,4) ) +transpose(((step((transpose(transpose(shuffle(X) ,-5) ,-7) |shuffle((X+((transpose(X,-5) +transpose(X,4) ) +transpose(X,7) ) ) ) ) ,12) |transpose(transpose(transpose((transpose(X,-5) |((transpose(X,-5) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,4) ,4) ,-5) ) +transpose(transpose(((shuffle(transpose(((transpose(X,4) +transpose((X+transpose(X,12) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-7) ) |transpose((transpose(X,-7) |shuffle(X) ) ,-7) ) +transpose(echo((X+transpose(shuffle(X) ,12) ) ,4,6) ,7) ) ,4) ,7) ) ,7) ) ,12) +transpose(((arpeggio((echo((shuffle(X) |X) ,4,6) +transpose((((transpose(arpeggio(X) ,4) +transpose((transpose(X,-5) +echo(X,4,6) ) ,12) ) +transpose(transpose(transpose((X|X) ,-5) ,4) ,4) ) +transpose(transpose(transpose(transpose(X,-5) ,4) ,-7) ,7) ) ,-7) ) ) |(((arpeggio(X) +transpose(((transpose(X,-7) +transpose((X|X) ,4) ) +transpose((X+X) ,7) ) ,12) ) +shuffle(X) ) |(step(((X+X) +transpose((X+X) ,7) ) ,12) |arpeggio(transpose(transpose(((X+transpose(transpose(X,4) ,12) ) |(X+transpose(echo(X,4,6) ,7) ) ) ,-5) ,-5) ) ) ) ) |arpeggio((transpose(((X|X) |(transpose(X,4) +transpose(X,12) ) ) ,-7) +((X+X) |transpose((X|X) ,4) ) ) ) ) ,7) ) +transpose(((transpose(((transpose((transpose((transpose((transpose(X,-5) |shuffle(X) ) ,-7) +transpose(((X+transpose(X,12) ) |transpose(X,-7) ) ,12) ) ,-5) |(echo((arpeggio(shuffle((X|X) ) ) |step(X,12) ) ,4,6) +transpose((transpose(shuffle((X|(X+transpose(X,7) ) ) ) ,-5) +transpose(step(((X|X) |echo(X,4,6) ) ,12) ,12) ) ,7) ) ) ,-7) +transpose((((X+transpose(X,12) ) +transpose(step(X,12) ,7) ) |((arpeggio(X) +transpose(shuffle((X|X) ) ,4) ) +transpose(((X|X) |(X+transpose(X,12) ) ) ,7) ) ) ,4) ) +transpose((((transpose(arpeggio(arpeggio(X) ) ,-5) +((((X+transpose(X,7) ) +transpose((X|X) ,7) ) +X) +transpose(((X+X) +transpose(transpose(X,-7) ,7) ) ,-5) ) ) +transpose(((transpose(step(step(X,12) ,12) ,4) +(transpose(X,-7) +transpose((X+transpose((X+X) ,12) ) ,7) ) ) +transpose(((X+(X+transpose(X,12) ) ) |arpeggio(X) ) ,12) ) ,12) ) |transpose(transpose(step(echo(transpose(transpose(X,-5) ,4) ,4,6) ,12) ,4) ,-5) ) ,7) ) ,-5) +transpose(transpose(arpeggio(transpose(((((transpose(echo(echo(echo(X,4,6) ,4,6) ,4,6) ,4) |transpose(arpeggio((X+X) ) ,-7) ) +transpose(((transpose(transpose((X+X) ,-7) ,-7) |((echo(X,4,6) +transpose(transpose(X,-7) ,-7) ) |((echo(X,4,6) +X) +(X|(X+transpose(X,12) ) ) ) ) ) +step(X,12) ) ,4) ) +transpose((((transpose(X,4) +transpose(transpose(X,4) ,7) ) +transpose(transpose(shuffle(transpose(X,-5) ) ,4) ,12) ) +transpose(step(transpose(((X|X) +transpose(((X+X) +transpose((X|X) ,7) ) ,7) ) ,-7) ,12) ,7) ) ,7) ) +transpose(step(echo((((X+transpose(X,4) ) +transpose(step(X,12) ,7) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) ,4,6) ,12) ,12) ) ,-7) ) ,-5) ,4) ) +transpose((step(((step(echo(((transpose(transpose(X,4) ,-5) +transpose((step(X,12) +transpose(transpose(arpeggio(X) ,4) ,12) ) ,4) ) +transpose((echo(X,4,6) +transpose(X,7) ) ,7) ) ,4,6) ,12) +transpose(transpose((transpose(transpose(transpose(transpose(transpose(X,-7) ,4) ,4) ,-5) ,-5) +shuffle(((((X+step(X,12) ) +transpose(transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,-5) ,4) ) +transpose(transpose((X+X) ,-5) ,7) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) ) ) ,-5) ,4) ) +transpose(transpose(step(transpose(shuffle((((X+transpose(X,7) ) +transpose(transpose(X,-7) ,4) ) +transpose(echo((X+X) ,4,6) ,7) ) ) ,4) ,12) ,4) ,7) ) ,12) +transpose(((shuffle(((X|(((((arpeggio(X) +transpose(X,7) ) +transpose(transpose(X,4) ,4) ) +transpose(transpose((X|transpose(X,-5) ) ,4) ,7) ) +transpose(((X|X) |(X+transpose(X,12) ) ) ,4) ) +transpose(transpose(transpose(X,-7) ,4) ,7) ) ) |(step((X|X) ,12) +transpose(step(((transpose((X|X) ,-7) +transpose(echo(transpose(X,-7) ,4,6) ,4) ) +transpose(transpose(X,-5) ,7) ) ,12) ,4) ) ) ) +transpose(((echo(transpose((transpose((X+X) ,4) |((X+X) |X) ) ,4) ,4,6) +transpose((((((X+transpose(X,12) ) +transpose(shuffle(X) ,7) ) +arpeggio(X) ) +transpose(transpose(X,4) ,12) ) |transpose(arpeggio(X) ,4) ) ,12) ) +transpose(transpose((transpose(transpose(transpose((X+transpose(X,12) ) ,4) ,-7) ,-5) +(transpose(echo((shuffle(step(X,12) ) +transpose(transpose(X,-5) ,-7) ) ,4,6) ,-7) +transpose((transpose(X,4) |transpose(transpose(((X+X) +transpose((X+transpose(X,12) ) ,7) ) ,-7) ,-7) ) ,7) ) ) ,4) ,12) ) ,12) ) +transpose((echo(transpose((transpose(arpeggio((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(shuffle(X) ,7) ) ) ,-5) |(transpose(X,-5) |transpose(transpose(transpose((X+transpose(X,7) ) ,-7) ,4) ,4) ) ) ,-5) ,4,6) +transpose(echo(shuffle((((transpose(X,4) |transpose(transpose(shuffle(X) ,4) ,4) ) +((echo((X+transpose(X,12) ) ,4,6) +X) +transpose(echo(X,4,6) ,12) ) ) +transpose(arpeggio((X+transpose(X,12) ) ) ,12) ) ) ,4,6) ,12) ) ,12) ) ,12) ) ,7) ) ,4) ) +transpose(arpeggio((transpose(((transpose(transpose((((X+transpose(X,7) ) +(X|X) ) +transpose(echo(step(X,12) ,4,6) ,12) ) ,-5) ,4) +transpose((shuffle(((X+X) +transpose(step((X+transpose(X,7) ) ,12) ,7) ) ) +transpose(transpose(((transpose(X,4) +(shuffle(X) |X) ) |transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(shuffle(X) ,12) ) ,-5) ) ,4) ,12) ) ,4) ) +transpose(((((arpeggio(X) |(X+transpose(X,12) ) ) |(transpose((X|X) ,-5) |(arpeggio((X+X) ) +transpose((X|arpeggio(X) ) ,7) ) ) ) +transpose(echo((transpose(shuffle(X) ,-7) |((transpose(X,4) +transpose(X,7) ) +arpeggio((echo(X,4,6) +transpose(X,7) ) ) ) ) ,4,6) ,4) ) +transpose((transpose(transpose((X|X) ,-5) ,-7) +((transpose(X,-7) +X) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +X) ,12) ) ) ,7) ) ,7) ) ,-7) |transpose(((((transpose(((X|X) |step(X,12) ) ,-5) +transpose(transpose(step(transpose((transpose(X,-7) +transpose(shuffle(X) ,12) ) ,4) ,12) ,-5) ,4) ) +transpose(shuffle((arpeggio(shuffle((X|X) ) ) +transpose((step(X,12) +transpose(X,12) ) ,4) ) ) ,7) ) +transpose(step(transpose((X|X) ,-7) ,12) ,4) ) +transpose((transpose((transpose(X,-5) +X) ,4) +shuffle((transpose(shuffle(X) ,4) +transpose(shuffle(X) ,12) ) ) ) ,7) ) ,-7) ) ) ,7) ) ,-7) ,-7) ) ,4) +(((transpose((arpeggio(X) |transpose(step(X,12) ,-7) ) ,-5) |((shuffle((shuffle((X|X) ) |(((transpose(X,-5) |shuffle((X+transpose(X,7) ) ) ) +(X|X) ) +transpose((transpose(X,-7) +transpose(((X+X) +X) ,-5) ) ,7) ) ) ) +transpose(transpose(transpose(echo(shuffle(shuffle(X) ) ,4,6) ,-5) ,-5) ,4) ) +transpose(transpose((echo((((X|X) +echo(X,4,6) ) +transpose(arpeggio(X) ,-7) ) ,4,6) +transpose((X+transpose((X+transpose(X,12) ) ,12) ) ,7) ) ,-7) ,7) ) ) |transpose(((transpose(((transpose((transpose(transpose((echo(X,4,6) +transpose(X,12) ) ,-5) ,4) +transpose((((X+transpose(X,12) ) +transpose(X,4) ) +transpose((X+transpose(X,7) ) ,7) ) ,7) ) ,4) +((transpose(((X+transpose(transpose(X,-5) ,12) ) +transpose((X+transpose(X,7) ) ,12) ) ,-5) +arpeggio(transpose(X,-5) ) ) +transpose(transpose(arpeggio(transpose((arpeggio(X) +transpose(X,-7) ) ,-7) ) ,-7) ,7) ) ) |shuffle((transpose((transpose(X,-7) +transpose((X+transpose(X,7) ) ,12) ) ,4) +transpose(transpose(transpose(((X|transpose(X,4) ) +step((X|X) ,12) ) ,-5) ,-7) ,12) ) ) ) ,4) |((transpose(((((X+transpose(((X+transpose(X,12) ) |transpose(X,-5) ) ,7) ) |(echo(X,4,6) +echo(transpose(X,4) ,4,6) ) ) +(((X+transpose(X,4) ) +transpose((X+X) ,7) ) +X) ) |step(transpose(X,4) ,12) ) ,4) +transpose(transpose((((step(X,12) +transpose((X+(X+transpose(X,12) ) ) ,7) ) +((shuffle(X) +echo(X,4,6) ) +transpose(echo(X,4,6) ,7) ) ) |((((X+X) +transpose(arpeggio(step(X,12) ) ,12) ) +arpeggio(arpeggio(shuffle(X) ) ) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,12) ) ) ,4) ,12) ) |shuffle(transpose(transpose(((X+X) +transpose((X+transpose(X,7) ) ,12) ) ,4) ,-5) ) ) ) |shuffle((((transpose(transpose(transpose(X,-5) ,-7) ,-5) +transpose(transpose(((shuffle(arpeggio(X) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose(transpose((X+X) ,-5) ,7) ) ,-7) ,4) ) +transpose((transpose(arpeggio(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X|X) ,12) ) ,-7) ) ,-7) +transpose(((X+X) +transpose(arpeggio(echo(arpeggio(X) ,4,6) ) ,12) ) ,12) ) ,4) ) +transpose(transpose((transpose(X,4) |transpose(step(transpose(X,4) ,12) ,4) ) ,-7) ,7) ) ) ) ,4) ) |shuffle(((transpose((transpose((((((X|X) +transpose((X+transpose(X,7) ) ,12) ) +transpose(((X|transpose(X,-5) ) |((shuffle(X) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,4) ) +transpose(((transpose(X,-7) +transpose(transpose(X,-5) ,4) ) +transpose(step(X,12) ,7) ) ,7) ) +transpose((transpose(echo(transpose(X,-5) ,4,6) ,4) +transpose(step(((X+X) |X) ,12) ,7) ) ,7) ) ,-5) +(transpose(echo(X,4,6) ,4) +transpose(transpose(X,4) ,7) ) ) ,-7) +transpose(arpeggio(echo(shuffle((transpose(((transpose(X,-5) |(((X+transpose(X,7) ) +transpose(X,4) ) +transpose((X+X) ,7) ) ) |echo(step(X,12) ,4,6) ) ,4) +transpose((shuffle(((X+transpose((transpose(echo(X,4,6) ,-7) +shuffle(shuffle(X) ) ) ,4) ) +transpose((transpose(X,-7) |transpose(X,-7) ) ,7) ) ) |(echo(transpose((shuffle(X) +X) ,4) ,4,6) +transpose(transpose(transpose(transpose(X,4) ,-7) ,4) ,7) ) ) ,7) ) ) ,4,6) ) ,12) ) +transpose(transpose(step(transpose(((echo((transpose(transpose(step(transpose(X,-5) ,12) ,-7) ,4) |(arpeggio((shuffle(X) +transpose((X+X) ,12) ) ) +transpose((transpose(transpose(X,-7) ,-7) |((transpose(X,-7) +transpose(((X+transpose(X,7) ) |X) ,4) ) +transpose(arpeggio((X+transpose(X,7) ) ) ,7) ) ) ,7) ) ) ,4,6) +transpose(echo((step((X|X) ,12) |(((transpose(X,-5) +transpose(X,12) ) +transpose(step(X,12) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,4,6) ,4) ) +transpose(((shuffle(X) +transpose((transpose(X,-5) +echo(X,4,6) ) ,4) ) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ,7) ) ,-5) ,12) ,-7) ,7) ) ) ) )
random seed used was 187977150

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