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:
(transpose(shuffle(arpeggio((transpose((((arpeggio(((transpose((transpose(X,-5) +shuffle(X) ) ,4) +transpose(transpose(transpose(shuffle(X) ,4) ,-5) ,12) ) |(X+transpose(X,7) ) ) ) +transpose(transpose(transpose((((transpose(X,-7) +transpose(step(X,12) ,4) ) +transpose(transpose((arpeggio(X) |(X+transpose(X,7) ) ) ,-5) ,7) ) +transpose(arpeggio(X) ,12) ) ,4) ,-7) ,4) ) +transpose(((transpose(echo(X,4,6) ,-7) +transpose(X,12) ) +transpose(transpose(transpose(((X+X) +transpose((X|X) ,7) ) ,-7) ,-5) ,12) ) ,7) ) |(((((transpose((((transpose(X,-5) +shuffle(X) ) +transpose(shuffle(X) ,7) ) +transpose(transpose(transpose(X,-5) ,4) ,-7) ) ,-5) +transpose((transpose(arpeggio(transpose(transpose(X,-7) ,4) ) ,4) |transpose(echo(X,4,6) ,4) ) ,12) ) +transpose(shuffle(transpose((step(((transpose(X,-5) +transpose((X+X) ,4) ) +transpose(transpose(X,-5) ,7) ) ,12) +transpose((((X|X) +transpose(X,7) ) +transpose((X+transpose(transpose(X,4) ,12) ) ,4) ) ,7) ) ,-5) ) ,12) ) +transpose(echo(transpose((transpose(X,-7) +(X|X) ) ,-5) ,4,6) ,-5) ) +(arpeggio(((((X+transpose(X,12) ) +transpose(transpose(X,-5) ,12) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ) ) +(transpose(transpose(echo(X,4,6) ,-5) ,-5) +(((((transpose(X,-7) +transpose(echo(X,4,6) ,4) ) +transpose((X+X) ,7) ) +transpose(((X|X) +transpose(X,12) ) ,4) ) +transpose((transpose(X,-7) |transpose(X,4) ) ,7) ) +transpose((((X+transpose(transpose(X,-5) ,7) ) +transpose(transpose((X+X) ,-5) ,12) ) +transpose(arpeggio(((transpose(X,-5) +transpose(shuffle(X) ,4) ) +transpose((X+X) ,7) ) ) ,7) ) ,7) ) ) ) ) +((transpose(transpose(shuffle(((X+X) +transpose(transpose(transpose(X,-5) ,4) ,7) ) ) ,-5) ,-5) +transpose(transpose(arpeggio(transpose((arpeggio(transpose(X,-5) ) +transpose(step(transpose(X,4) ,12) ,7) ) ,-5) ) ,4) ,12) ) +transpose(arpeggio((echo(transpose(echo(transpose(X,4) ,4,6) ,4) ,4,6) +transpose((shuffle(X) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) |(X|X) ) +transpose(shuffle(X) ,7) ) ,7) ) ,-5) ) ) ,-7) ) ) ) ,-7) +(((transpose(transpose((arpeggio((arpeggio(transpose(X,4) ) +transpose(transpose(step(X,12) ,-5) ,12) ) ) +transpose(transpose((transpose((X+transpose(X,12) ) ,4) +(X+X) ) ,-7) ,12) ) ,4) ,-7) +transpose((transpose(transpose(echo((((X|arpeggio(X) ) +transpose(transpose(((X+transpose(X,7) ) +transpose(((X+transpose(step(X,12) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) ,-5) ,7) ) +transpose((step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) |step(((X+arpeggio(X) ) +transpose((((X+transpose(X,7) ) +transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) ,7) ) ,12) ) ,12) ) ,4,6) ,4) ,-5) +transpose(transpose(step((((X+X) +transpose((X+X) ,7) ) |transpose(transpose(X,4) ,4) ) ,12) ,-7) ,12) ) ,4) ) +transpose(arpeggio(arpeggio(transpose((((((X+X) |(X+X) ) |(X+X) ) +transpose(transpose(X,4) ,4) ) +transpose((X|step(X,12) ) ,7) ) ,-7) ) ) ,7) ) +transpose((transpose(((((transpose(X,4) +transpose(((X+X) |X) ,4) ) +transpose(step((X+transpose((X|X) ,12) ) ,12) ,7) ) +transpose((X+transpose(transpose(X,-5) ,12) ) ,4) ) +transpose((transpose(X,4) |step(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ) ,7) ) ,-7) +transpose(((((X+transpose(X,7) ) +X) +step(X,12) ) |transpose(arpeggio(step(step(step(X,12) ,12) ,12) ) ,-7) ) ,12) ) ,-7) ) ) ) ) ,-7) +transpose((transpose(transpose(arpeggio((transpose(step(step((echo(((echo((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) ,4,6) |transpose(step((X+transpose(transpose(X,4) ,12) ) ,12) ,4) ) +((X+X) +transpose(transpose((X+transpose((transpose(X,4) |transpose(X,-5) ) ,12) ) ,4) ,7) ) ) ,4,6) +transpose(step((arpeggio(((transpose(X,-5) +transpose(X,7) ) +transpose(((X|X) +echo(X,4,6) ) ,12) ) ) +(((X+transpose((X+transpose(X,12) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose(transpose(X,4) ,-7) ) ) ,12) ,12) ) ,12) ,12) ,-7) |((((transpose(transpose(arpeggio(transpose(X,4) ) ,-5) ,-5) +(((((X|X) |transpose(X,4) ) +(((transpose((echo(X,4,6) +transpose(X,12) ) ,-5) +(transpose(X,-5) +X) ) +transpose(step(X,12) ,-5) ) |transpose(transpose(X,-7) ,-7) ) ) +transpose(transpose((step(((transpose(X,-5) +X) |(X+transpose(step(transpose(X,4) ,12) ,12) ) ) ,12) +transpose((step(transpose((X+transpose(X,7) ) ,-5) ,12) +transpose(transpose(echo(X,4,6) ,4) ,12) ) ,12) ) ,-7) ,4) ) +transpose(transpose(((step(transpose(((X|X) +transpose(X,4) ) ,4) ,12) +transpose((transpose(X,-5) +transpose(X,7) ) ,12) ) +(transpose(transpose(X,4) ,-7) +step((X+transpose(X,12) ) ,12) ) ) ,-5) ,7) ) ) |transpose(transpose(echo(((transpose(X,-5) +transpose((transpose(X,-7) |(X|X) ) ,12) ) |(X+transpose(X,12) ) ) ,4,6) ,4) ,4) ) +transpose(transpose(arpeggio((((X+transpose(X,12) ) +(transpose(X,-7) +transpose(X,-7) ) ) +transpose(step(X,12) ,12) ) ) ,-7) ,4) ) +transpose(echo(echo(((((transpose(X,4) |transpose(X,4) ) |echo(step(transpose((arpeggio(X) +transpose((X+X) ,7) ) ,-7) ,12) ,4,6) ) +(step(transpose(transpose(transpose(X,-7) ,4) ,4) ,12) +transpose(transpose(transpose(X,4) ,-5) ,-5) ) ) +transpose((arpeggio(((shuffle((X+transpose(X,12) ) ) |X) +(((((X|X) +transpose(transpose(X,4) ,4) ) +transpose(X,7) ) +transpose(((X+transpose((X|X) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,4) ) +transpose(arpeggio(X) ,7) ) ) ) |transpose(((X+X) +(transpose(X,-5) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) ,4) ) ,4) ) ,4,6) ,4,6) ,7) ) ) ) ,-5) ,-7) +transpose((step(((transpose((transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,-5) ,4) +(transpose((X+((X+transpose(X,12) ) |(X|X) ) ) ,-5) +((step((X+transpose(step(X,12) ,12) ) ,12) +transpose(shuffle(X) ,12) ) +transpose(step(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ,12) ,12) ) ) ) ,-5) +transpose(((transpose(transpose((transpose((shuffle((transpose(X,-5) +X) ) +arpeggio(shuffle(step(X,12) ) ) ) ,-5) |transpose(transpose(X,-7) ,-7) ) ,4) ,-7) |(((((X+X) +X) |shuffle(step(X,12) ) ) |transpose(transpose(echo(X,4,6) ,4) ,-5) ) |echo(transpose((transpose(transpose(echo(X,4,6) ,-5) ,-5) +transpose(transpose((arpeggio(X) +transpose(X,7) ) ,-7) ,12) ) ,-5) ,4,6) ) ) +transpose(((transpose((step((step((X+transpose((X+transpose(X,7) ) ,12) ) ,12) |shuffle(transpose((transpose(X,-7) +transpose(X,7) ) ,-5) ) ) ,12) +((transpose(X,-5) +transpose(shuffle((X+X) ) ,7) ) |(((X+transpose(step(X,12) ,4) ) +transpose(shuffle(X) ,7) ) +X) ) ) ,-7) +transpose(((transpose(transpose(X,-5) ,-7) +transpose(echo((echo((transpose(X,4) +transpose(transpose(X,-5) ,7) ) ,4,6) +transpose(step((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) ,12) ,12) ) ,4,6) ,4) ) +transpose(step((echo(X,4,6) +transpose(transpose(X,-5) ,12) ) ,12) ,7) ) ,4) ) +transpose(((shuffle(step(((X+echo(X,4,6) ) |(transpose(X,-7) |X) ) ,12) ) +arpeggio((transpose(arpeggio(transpose(transpose(X,-5) ,4) ) ,4) |((X|transpose(X,4) ) +(((X+transpose(X,4) ) +transpose(X,7) ) +arpeggio(X) ) ) ) ) ) +transpose((transpose(transpose(X,-5) ,-7) |shuffle(step(X,12) ) ) ,12) ) ,7) ) ,12) ) ,4) ) +transpose((((step(((step(arpeggio(X) ,12) +transpose(arpeggio(X) ,12) ) +transpose(shuffle((X|X) ) ,12) ) ,12) |(transpose(transpose((X+X) ,-5) ,-5) |arpeggio(transpose(arpeggio((X+X) ) ,4) ) ) ) +transpose((((((X+transpose((transpose(X,-5) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) |(X|echo(X,4,6) ) ) +transpose(transpose(step(transpose((transpose(X,-5) |((X|X) +(X|X) ) ) ,4) ,12) ,-5) ,4) ) +transpose(transpose(transpose(transpose(shuffle(transpose(X,-7) ) ,-7) ,4) ,-5) ,7) ) +((transpose(X,-7) +transpose(transpose((shuffle(transpose(X,-5) ) +((X|X) |transpose(X,-5) ) ) ,4) ,4) ) +transpose(echo((transpose(X,4) +transpose(X,12) ) ,4,6) ,7) ) ) ,12) ) |(arpeggio((echo(((X|X) +((X+transpose(X,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,4,6) |transpose((transpose((X|X) ,4) +transpose(arpeggio(X) ,12) ) ,-7) ) ) |(((transpose(echo(transpose(X,-7) ,4,6) ,-5) |arpeggio(transpose(((transpose(X,-7) |transpose(X,-5) ) +((X+transpose(X,12) ) +shuffle((X+X) ) ) ) ,4) ) ) +transpose(transpose(arpeggio((X+transpose((X+X) ,12) ) ) ,-5) ,12) ) +transpose(arpeggio(transpose(transpose(arpeggio(((transpose(X,-7) +transpose(X,7) ) +X) ) ,-5) ,-7) ) ,7) ) ) ) ,7) ) ,12) +transpose(transpose(step((shuffle(((transpose(((shuffle(X) +transpose(transpose(transpose(X,-7) ,-5) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ,4) +transpose((arpeggio(transpose(echo(X,4,6) ,-5) ) +transpose(step(shuffle(X) ,12) ,7) ) ,7) ) |(transpose(transpose(transpose(X,4) ,-7) ,4) |transpose(echo(X,4,6) ,-7) ) ) ) +shuffle(((transpose(X,4) |transpose(transpose(X,4) ,-5) ) +transpose(((transpose(X,-7) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ) ) ,12) ,-5) ,7) ) ,7) ) ,12) )
random seed used was 267982056

NOTE: Generated phrase was too large ( 6940 ) , it has been truncated at 5000 notes. EXPR = (arpeggio(shuffle(((arpeggio(transpose(transpose(echo(((((X|X) |step(X,12) ) |transpose(X,-5) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,4,6) ,-5) ,-5) ) |shuffle(transpose(((step((shuffle(((X+X) +X) ) |step(X,12) ) ,12) +step(transpose((transpose(X,4) |step(echo(X,4,6) ,12) ) ,-7) ,12) ) |(((transpose((transpose(((X+transpose(X,7) ) |(X|X) ) ,4) |(X+shuffle(X) ) ) ,-5) +transpose(((arpeggio(((X+transpose((X+transpose(X,12) ) ,4) ) +transpose((X+X) ,7) ) ) +transpose(transpose(arpeggio(X) ,-7) ,4) ) +transpose(transpose(transpose(step(X,12) ,-5) ,-5) ,7) ) ,7) ) +transpose(transpose(((transpose(transpose(shuffle(transpose(X,-7) ) ,4) ,-7) +transpose(step(transpose(X,-5) ,12) ,4) ) +transpose((shuffle(echo(echo(X,4,6) ,4,6) ) +transpose((step(X,12) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,12) ) ,7) ) ,-5) ,7) ) +transpose(transpose(transpose(transpose(transpose(transpose(X,-5) ,-5) ,-7) ,-5) ,4) ,12) ) ) ,4) ) ) +transpose((echo(step(X,12) ,4,6) |(step((step(transpose(transpose(transpose(transpose((X|X) ,-5) ,-7) ,-7) ,-5) ,12) |shuffle(transpose(transpose(X,4) ,-5) ) ) ,12) |(step(step(((transpose((step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) +X) ,-7) +step((X+transpose(X,-7) ) ,12) ) +transpose(transpose((X|X) ,4) ,12) ) ,12) ,12) +transpose(transpose(transpose(transpose(transpose(arpeggio((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) ) ,-5) ,-7) ,-5) ,-5) ,12) ) ) ) ,7) ) ) ) |transpose((echo(((shuffle((step(transpose((X+transpose(X,12) ) ,-5) ,12) +(transpose(X,-5) +transpose(transpose(step(X,12) ,4) ,12) ) ) ) +transpose(transpose(echo(X,4,6) ,-5) ,7) ) |((echo((step((X+transpose((X|X) ,12) ) ,12) +transpose((((X+transpose(X,12) ) +transpose((arpeggio(X) |transpose(X,-7) ) ,7) ) |echo(X,4,6) ) ,-7) ) ,4,6) +transpose(transpose((((X+transpose(((X+(X|X) ) +transpose((transpose(X,4) |arpeggio(X) ) ,12) ) ,12) ) +transpose(X,4) ) +transpose(X,7) ) ,-5) ,12) ) +((transpose((arpeggio(((transpose((X|X) ,-5) +transpose((X+X) ,-7) ) +(((transpose(X,4) +transpose(X,4) ) +transpose(X,7) ) +transpose((transpose(X,-5) |X) ,-7) ) ) ) +((arpeggio(transpose(X,-7) ) +arpeggio(X) ) +shuffle(((X|X) |((X+transpose(X,4) ) +transpose(X,7) ) ) ) ) ) ,-5) +transpose((((((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) +transpose((X|X) ,4) ) +transpose(shuffle((X+transpose(X,12) ) ) ,7) ) +transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) +transpose(transpose(X,-5) ,12) ) ,4) ) +transpose((transpose(((arpeggio(X) +transpose(echo((X+transpose(X,12) ) ,4,6) ,4) ) +transpose(transpose(X,-5) ,7) ) ,4) +transpose((shuffle(transpose(X,4) ) |arpeggio(transpose(X,-7) ) ) ,7) ) ,7) ) +echo(((echo(X,4,6) |(X|X) ) +((X+transpose(X,12) ) +transpose((arpeggio(echo(X,4,6) ) +(X+echo(X,4,6) ) ) ,7) ) ) ,4,6) ) ,4) ) +transpose(arpeggio(echo(transpose(transpose(transpose((X+transpose(X,12) ) ,4) ,-7) ,-5) ,4,6) ) ,7) ) ) ) ,4,6) |(step((transpose(((arpeggio(transpose((((transpose(X,4) +transpose(transpose(X,4) ,7) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose((X|X) ,7) ) ,-7) ) +transpose(step(echo((arpeggio((X+transpose(X,12) ) ) +(arpeggio(X) +X) ) ,4,6) ,12) ,4) ) +transpose(step(step(shuffle(arpeggio(X) ) ,12) ,12) ,7) ) ,-7) |(transpose(shuffle(step(transpose(((transpose(transpose((X+transpose(X,7) ) ,-7) ,4) +transpose((((X+transpose(X,7) ) |(X+transpose(X,7) ) ) +transpose(X,-7) ) ,4) ) +transpose((transpose(X,-5) +(transpose(X,4) |X) ) ,7) ) ,-5) ,12) ) ,4) +step(arpeggio(((transpose(transpose(transpose(transpose(X,-7) ,4) ,4) ,-5) |transpose(arpeggio(X) ,-7) ) |transpose((((X+transpose(X,12) ) +transpose(X,12) ) |((arpeggio(X) +transpose((X|X) ,12) ) +arpeggio(transpose(X,-7) ) ) ) ,4) ) ) ,12) ) ) ,12) |shuffle(transpose(transpose(transpose(shuffle((transpose(X,4) +echo(X,4,6) ) ) ,-5) ,4) ,4) ) ) ) ,-5) )
random seed used was 0

NOTE: Generated phrase was too large ( 5208 ) , it has been truncated at 5000 notes.


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