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:
Seed:
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Generations:
Phrase for X:
# of Tracks:
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After 20 generations the expression "X" became this:
((arpeggio((echo(step(shuffle(transpose(transpose(step((((X+transpose(step(transpose(X,-5) ,12) ,4) ) +transpose((transpose(X,-5) +shuffle(X) ) ,7) ) +(transpose(X,4) |X) ) ,12) ,-7) ,-5) ) ,12) ,4,6) +transpose(((transpose(shuffle((step(((((transpose(step(((X+transpose(transpose(X,-5) ,4) ) +transpose(echo(X,4,6) ,7) ) ,12) ,-7) +transpose(step(X,12) ,4) ) +transpose(shuffle(X) ,7) ) +transpose(shuffle(echo(arpeggio(transpose((((X+X) +transpose(X,4) ) +transpose(X,7) ) ,-5) ) ,4,6) ) ,4) ) +transpose(transpose(transpose(shuffle(X) ,-5) ,-5) ,7) ) ,12) +transpose((((((((((X|X) |X) +transpose(echo(arpeggio(X) ,4,6) ,4) ) +transpose(transpose(X,4) ,7) ) +transpose((echo(X,4,6) |X) ,7) ) +transpose(transpose((X+transpose(transpose(X,-7) ,7) ) ,-7) ,4) ) +transpose((shuffle(shuffle(transpose(X,-7) ) ) |step(transpose((((X+transpose(X,7) ) +transpose(step(transpose(X,-5) ,12) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-7) ,12) ) ,7) ) +transpose(transpose(transpose(transpose(echo(step(X,12) ,4,6) ,-5) ,4) ,-7) ,4) ) +transpose(step((shuffle(arpeggio(X) ) |X) ,12) ,7) ) ,12) ) ) ,4) +transpose(echo(shuffle(((transpose(transpose(((step(echo(X,4,6) ,12) +transpose(X,7) ) +transpose(echo(((X+transpose(X,4) ) +transpose((X|X) ,7) ) ,4,6) ,12) ) ,-7) ,4) +transpose((transpose((step(X,12) +transpose(step(X,12) ,7) ) ,-7) +transpose(transpose(transpose(transpose(X,-5) ,4) ,-7) ,7) ) ,12) ) |step((arpeggio((((X+transpose(X,12) ) +transpose((X|X) ,4) ) +transpose(arpeggio(X) ,7) ) ) +(arpeggio(arpeggio(X) ) |arpeggio((((X+X) +transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) ) ) ) ,12) ) ) ,4,6) ,4) ) +transpose(echo((transpose(shuffle(echo(shuffle(((transpose((step(X,12) +transpose((X+X) ,12) ) ,-7) +transpose(step((X+transpose(X,7) ) ,12) ,4) ) +transpose(((echo(X,4,6) +transpose(X,7) ) +transpose(arpeggio(transpose(X,-7) ) ,7) ) ,7) ) ) ,4,6) ) ,4) +step(transpose(((((((step((X|X) ,12) +transpose(step(X,12) ,4) ) +transpose((arpeggio(X) |X) ,7) ) |step((step(X,12) +transpose(step(X,12) ,7) ) ,12) ) +transpose(shuffle(transpose(transpose(X,-7) ,-5) ) ,7) ) |arpeggio(step(arpeggio(shuffle(X) ) ,12) ) ) +transpose(transpose(echo((transpose(transpose(X,-5) ,-7) +transpose(arpeggio(echo(X,4,6) ) ,12) ) ,4,6) ,4) ,7) ) ,-7) ,12) ) ,4,6) ,7) ) ,12) ) ) +shuffle((transpose(echo(transpose(shuffle(((arpeggio(echo((shuffle(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,4,6) ) +transpose(arpeggio(X) ,4) ) +transpose(step(X,12) ,7) ) ) ,4) ,4,6) ,-5) +(transpose((((((arpeggio(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ) |step(X,12) ) +transpose(shuffle((X+transpose(echo(arpeggio(X) ,4,6) ,12) ) ) ,4) ) +transpose(shuffle((arpeggio(transpose(arpeggio(X) ,4) ) +((X+transpose(arpeggio(X) ,4) ) +transpose(arpeggio(X) ,7) ) ) ) ,7) ) +transpose(transpose(transpose(shuffle(arpeggio(arpeggio(X) ) ) ,-7) ,-7) ,4) ) +transpose(transpose(transpose(step((X|X) ,12) ,-5) ,4) ,7) ) ,4) +(((X|X) |(step(transpose((X|X) ,4) ,12) +(((X+X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ) +transpose(((shuffle(transpose(transpose(step(X,12) ,-7) ,4) ) +transpose((step(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,12) +transpose(transpose(step(echo(X,4,6) ,12) ,-5) ,12) ) ,4) ) +transpose(arpeggio(echo(shuffle(echo(X,4,6) ) ,4,6) ) ,7) ) ,12) ) ) ) ) ) |transpose(arpeggio(((((((echo(transpose((((transpose((((step((X|X) ,12) +transpose(arpeggio(arpeggio(X) ) ,7) ) +transpose(transpose(arpeggio(X) ,-7) ,4) ) +transpose(((step(X,12) +arpeggio(X) ) +transpose(X,7) ) ,7) ) ,-7) +transpose(step((shuffle(X) +transpose(transpose(X,4) ,7) ) ,12) ,4) ) +transpose(step(shuffle(shuffle(X) ) ,12) ,7) ) +transpose(transpose((((((X+X) +transpose(step(X,12) ,4) ) +transpose(X,7) ) +transpose(transpose(transpose(X,4) ,4) ,4) ) +transpose((X+X) ,7) ) ,-7) ,-5) ) ,-5) ,4,6) +transpose(((transpose(transpose((step(step(X,12) ,12) |((((X|X) |X) |echo(X,4,6) ) +echo(transpose(transpose(X,4) ,-7) ,4,6) ) ) ,-7) ,-5) +transpose(step(echo(shuffle((step(shuffle(X) ,12) |echo(step(transpose(X,4) ,12) ,4,6) ) ) ,4,6) ,12) ,4) ) +transpose((((((shuffle(arpeggio(X) ) +transpose(transpose(X,-7) ,4) ) +transpose(((shuffle(X) +transpose(step((X+transpose(X,7) ) ,12) ,4) ) +transpose(echo(arpeggio(X) ,4,6) ,7) ) ,7) ) +(((transpose(((transpose(shuffle(X) ,-5) +transpose(echo(echo(X,4,6) ,4,6) ,4) ) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ,-5) +arpeggio(step(arpeggio(X) ,12) ) ) +transpose(arpeggio(shuffle(echo((echo(X,4,6) +X) ,4,6) ) ) ,4) ) +transpose(shuffle(shuffle(X) ) ,7) ) ) +transpose(transpose(arpeggio(echo(arpeggio((transpose((X+transpose(X,12) ) ,-7) +shuffle(X) ) ) ,4,6) ) ,-7) ,4) ) +transpose((((echo(step(transpose((X+X) ,4) ,12) ,4,6) |echo((X+X) ,4,6) ) +transpose((echo((((transpose(X,-7) +transpose((X+transpose(X,7) ) ,4) ) +transpose(arpeggio(arpeggio(X) ) ,7) ) +transpose(shuffle(echo(X,4,6) ) ,12) ) ,4,6) +echo((shuffle(echo(X,4,6) ) +transpose(transpose(transpose((X+transpose(X,7) ) ,-5) ,-5) ,12) ) ,4,6) ) ,7) ) |arpeggio(shuffle(((echo((((X+transpose(X,7) ) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) ,4,6) +transpose(transpose(((X+transpose(arpeggio(X) ,4) ) +transpose(X,7) ) ,-7) ,4) ) +transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,7) ) ) ) ) ,7) ) ,7) ) ,4) ) +transpose((echo(((((arpeggio(echo((X+transpose(X,-7) ) ,4,6) ) +((echo(arpeggio(step(X,12) ) ,4,6) +transpose(echo(arpeggio(arpeggio(X) ) ,4,6) ,4) ) +transpose(((((X+transpose(X,7) ) +X) +transpose(X,4) ) +transpose(shuffle(shuffle(X) ) ,7) ) ,7) ) ) +transpose((((transpose(((arpeggio(X) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) ,-5) |((((transpose(X,-5) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) +transpose((transpose(X,4) +X) ,4) ) +transpose((shuffle(X) +transpose(echo(X,4,6) ,7) ) ,7) ) ) +transpose(shuffle(step(transpose(transpose(X,-7) ,-5) ,12) ) ,7) ) +echo(shuffle(echo(transpose(X,4) ,4,6) ) ,4,6) ) ,12) ) +transpose(((step(((step(X,12) +transpose(echo(X,4,6) ,4) ) +transpose(transpose(X,4) ,7) ) ,12) +((X+X) +transpose(((((echo(X,4,6) +transpose(step(X,12) ,4) ) +transpose(X,7) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose(shuffle(X) ,7) ) ,7) ) ) |((shuffle(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ) +transpose(step(shuffle((transpose(X,4) +transpose(shuffle(X) ,12) ) ) ,12) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,4) ) +transpose(arpeggio(transpose(transpose(echo(X,4,6) ,-5) ,-7) ) ,7) ) ,4,6) +transpose(step(transpose(shuffle(((echo(transpose(shuffle(((((step((X+transpose(X,7) ) ,12) +transpose(arpeggio(echo(X,4,6) ) ,4) ) +transpose(shuffle(X) ,7) ) +transpose(transpose(transpose((X|X) ,4) ,4) ,4) ) +transpose(step(X,12) ,7) ) ) ,-7) ,4,6) +transpose(((shuffle(shuffle(X) ) +transpose(transpose(shuffle((X+transpose(X,7) ) ) ,-7) ,4) ) +transpose((X+X) ,7) ) ,4) ) +transpose(arpeggio(arpeggio(step(shuffle(transpose(shuffle((X+transpose(X,12) ) ) ,4) ) ,12) ) ) ,7) ) ) ,4) ,12) ,7) ) ,7) ) +transpose(step(shuffle((echo(transpose(((((X+transpose(step(X,12) ,4) ) +transpose(((transpose(X,-7) +transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose(echo((X+transpose(X,12) ) ,4,6) ,4) ) +transpose((echo(X,4,6) |shuffle(((echo(X,4,6) +transpose(X,4) ) +transpose(X,7) ) ) ) ,7) ) ,4) ,4,6) +transpose((((shuffle(transpose(transpose(X,4) ,-7) ) +((arpeggio((step((X+X) ,12) +shuffle(transpose(X,-7) ) ) ) +transpose(arpeggio(step(X,12) ) ,4) ) +transpose((X+step((X+transpose(X,12) ) ,12) ) ,7) ) ) +transpose((step(((X+transpose(arpeggio(X) ,4) ) +transpose((X|X) ,7) ) ,12) |transpose((echo(X,4,6) +(shuffle(arpeggio(X) ) +transpose(((step(X,12) +transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) ,12) ) ) ,4) ) ,4) ) +transpose((transpose(shuffle(X) ,4) +transpose((transpose(shuffle(X) ,4) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ,12) ) ,7) ) ,7) ) ) ,12) ,4) ) +transpose(echo(((shuffle((((echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) +transpose(arpeggio(X) ,4) ) +transpose(transpose(echo(X,4,6) ,-7) ,7) ) +transpose((transpose(X,4) +transpose(shuffle(X) ,12) ) ,4) ) ) |transpose(arpeggio(step(shuffle((arpeggio(X) +shuffle(X) ) ) ,12) ) ,4) ) +transpose(shuffle(transpose(((((transpose(step(X,12) ,-5) |(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) ,4) |transpose(echo(X,4,6) ,-7) ) ) +transpose(echo((step(transpose(echo(X,4,6) ,-5) ,12) |((transpose(X,-5) |(X+transpose(X,12) ) ) +transpose(step(step(X,12) ,12) ,12) ) ) ,4,6) ,12) ) +transpose(arpeggio(transpose(X,-5) ) ,4) ) +transpose(shuffle(((echo((X+transpose(X,12) ) ,4,6) +transpose(step((X|X) ,12) ,4) ) +transpose(shuffle((X|X) ) ,7) ) ) ,7) ) ,4) ) ,-5) ) ,4,6) ,7) ) +transpose(echo(((shuffle((step(((X|X) +transpose(arpeggio(X) ,7) ) ,12) +transpose(echo(transpose(((transpose(X,4) +transpose(X,4) ) +transpose((X|X) ,7) ) ,4) ,4,6) ,7) ) ) +transpose(arpeggio((((arpeggio(((echo(X,4,6) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(transpose(X,4) ,7) ) ) +transpose(arpeggio(arpeggio(arpeggio((arpeggio(X) |step(X,12) ) ) ) ) ,4) ) +transpose(transpose((step(step(transpose(arpeggio(X) ,4) ,12) ,12) +transpose(echo(echo((((X+transpose(X,4) ) +transpose(X,7) ) +X) ,4,6) ,4,6) ,7) ) ,4) ,7) ) |(((transpose(shuffle(X) ,4) +transpose(transpose(((X+transpose(step(X,12) ,4) ) +transpose(X,7) ) ,-5) ,4) ) +transpose(echo(step((arpeggio(transpose(X,-7) ) +transpose(X,-7) ) ,12) ,4,6) ,7) ) +transpose(transpose(shuffle((((X+transpose(X,12) ) +transpose(transpose(X,4) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,4) ,12) ) ) ) ,12) ) +(arpeggio(step(transpose(transpose(echo(transpose(transpose(step(X,12) ,-5) ,-7) ,4,6) ,-5) ,-5) ,12) ) |(((transpose(step((X+X) ,12) ,-7) +arpeggio(echo(echo(X,4,6) ,4,6) ) ) +transpose(step(step((step(transpose(X,-7) ,12) |arpeggio(X) ) ,12) ,12) ,4) ) +transpose((transpose(shuffle(step(X,12) ) ,-5) |echo(X,4,6) ) ,7) ) ) ) ,4,6) ,4) ) +transpose(transpose((arpeggio((arpeggio(transpose(X,-7) ) +(arpeggio((X+transpose(step(X,12) ,12) ) ) +((transpose((X|X) ,-5) +transpose(X,4) ) +transpose(X,7) ) ) ) ) +transpose(shuffle(transpose(step(arpeggio(transpose(transpose((X+transpose(X,7) ) ,-7) ,-5) ) ,12) ,-7) ) ,12) ) ,-5) ,7) ) ) ,4) )
random seed used was 105330346

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