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:
Randomize seed:
Generations:
Phrase for X:
# of Tracks:
Randomize patches:
 

Results may not appear for a few seconds.
Be patient!
Do you like this result? Do you want to let other people listen to it?

Save this one in the
Tune Trove!

See what's already
in the Tune Trove!

After 15 generations the expression "X" became this:
transpose(transpose(arpeggio(transpose((transpose(transpose(transpose(((X+transpose(X,12) ) |echo(X,4,6) ) ,4) ,4) ,-5) +transpose(((echo(((((transpose(X,-5) +transpose(transpose(X,-5) ,12) ) |arpeggio((X|X) ) ) +transpose((step(transpose(X,4) ,12) +(echo(X,4,6) +transpose(X,4) ) ) ,4) ) +transpose(transpose(shuffle(X) ,-7) ,7) ) ,4,6) +transpose(((transpose(transpose((X+X) ,-5) ,-5) +transpose(transpose((X|X) ,4) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4) ) +transpose(((transpose((shuffle(X) +transpose((X+transpose(X,7) ) ,12) ) ,4) +transpose((arpeggio(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ) +((shuffle(X) +transpose(transpose(arpeggio(X) ,4) ,4) ) +transpose(echo(X,4,6) ,7) ) ) ,4) ) +transpose(arpeggio((transpose(X,4) |(X|X) ) ) ,7) ) ,7) ) ,12) ) ,-5) ) ,-5) ,4)
random seed used was 19 EXPR = (arpeggio(step(transpose(transpose((((shuffle(transpose(X,-5) ) +transpose(arpeggio(step(transpose((X+X) ,-5) ,12) ) ,4) ) +transpose((((arpeggio(transpose(X,4) ) +transpose((transpose(X,4) +transpose((transpose(echo(X,4,6) ,4) +transpose(X,7) ) ,12) ) ,7) ) |(step((X+arpeggio(X) ) ,12) +transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(transpose(X,4) ,7) ) ,7) ) ) |(echo((X|X) ,4,6) |(shuffle(X) +transpose(X,4) ) ) ) ,7) ) +transpose(((echo(arpeggio((X+X) ) ,4,6) |((((X+X) +transpose(transpose(X,-7) ,7) ) +transpose(X,4) ) +transpose(transpose(transpose(X,-5) ,-5) ,12) ) ) +transpose((transpose(((transpose((X+X) ,4) +transpose(transpose((X+transpose(X,7) ) ,-5) ,4) ) +transpose(transpose(X,-7) ,7) ) ,-7) +X) ,12) ) ,12) ) ,-5) ,-7) ,12) ) |transpose((transpose(transpose(transpose(transpose(arpeggio((transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-7) +transpose(transpose(transpose(transpose(shuffle(X) ,4) ,4) ,4) ,7) ) ) ,-7) ,-5) ,-5) ,-5) +(arpeggio((transpose(X,-5) +transpose(((X+transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,-7) ) ) +arpeggio(echo(transpose(arpeggio((arpeggio((X+transpose(transpose(X,-7) ,12) ) ) |transpose((transpose(X,-5) +arpeggio(X) ) ,4) ) ) ,4) ,4,6) ) ) ) ,4) )
random seed used was 0 EXPR = step(transpose(((transpose((((transpose(((echo(X,4,6) +transpose((X+transpose(X,7) ) ,12) ) +transpose(((transpose(transpose(step(X,12) ,4) ,-7) +((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) +transpose((X+transpose(transpose(X,4) ,12) ) ,7) ) ) +transpose((transpose(X,4) +transpose(transpose(X,4) ,12) ) ,12) ) ,12) ) ,4) +transpose(transpose(((arpeggio(X) +((((X|X) +transpose(X,12) ) |transpose(X,-7) ) +transpose(echo(X,4,6) ,7) ) ) |((transpose(X,4) +transpose(X,12) ) |X) ) ,-7) ,4) ) +transpose((transpose((arpeggio((transpose(X,-5) +transpose(X,-5) ) ) |arpeggio((X+((X+transpose(transpose(X,-5) ,4) ) +transpose((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,7) ) ) ) ) ,-5) |(X|transpose(step((X+X) ,12) ,-5) ) ) ,4) ) +transpose(echo((arpeggio((step((X+X) ,12) |transpose(X,-5) ) ) |transpose(X,-5) ) ,4,6) ,7) ) ,4) +transpose(transpose(transpose(((((transpose(X,4) +echo(transpose(X,-5) ,4,6) ) +transpose((((transpose(transpose(X,4) ,-5) +transpose((X|echo(X,4,6) ) ,4) ) +transpose((X+transpose((X|X) ,12) ) ,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) ,12) ) +transpose((((transpose(shuffle(X) ,-5) +transpose((shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) |(X+X) ) ,7) ) |(((transpose((X|X) ,-5) +transpose(transpose(X,-5) ,7) ) +(echo(X,4,6) |arpeggio(X) ) ) +transpose(transpose(X,-5) ,4) ) ) |transpose(arpeggio(((echo((transpose(X,-5) +transpose(X,-7) ) ,4,6) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,-5) ,12) ) ,4) ) +transpose(transpose(((X+transpose(X,7) ) +transpose(transpose(X,-7) ,7) ) ,-5) ,7) ) ) ,4) ) ,4) ) +transpose(((((arpeggio(transpose(X,-7) ) +transpose(transpose(transpose(X,-7) ,-7) ,-5) ) +echo(transpose(echo(X,4,6) ,4) ,4,6) ) +transpose(((transpose(X,-5) |(X|X) ) +((transpose(transpose(X,-7) ,-5) +transpose(arpeggio(X) ,4) ) +transpose(transpose(step(X,12) ,4) ,7) ) ) ,7) ) |transpose(X,-5) ) ,7) ) ,4) ,-5) ,4) ) +transpose(transpose((((transpose((shuffle(step(((transpose(X,4) |X) |transpose(X,4) ) ,12) ) +transpose(echo(((X+X) |X) ,4,6) ,7) ) ,4) +(((transpose((((step(X,12) |X) +transpose(transpose((X+transpose(echo(X,4,6) ,12) ) ,-7) ,4) ) +transpose(transpose((transpose(X,4) |X) ,-7) ,7) ) ,-5) +transpose(((transpose(transpose(X,-7) ,-7) +transpose(X,12) ) +transpose(((transpose(X,4) |X) +transpose(((X|X) +transpose(X,-5) ) ,12) ) ,12) ) ,4) ) +transpose(echo((arpeggio(X) +X) ,4,6) ,7) ) +(X+transpose(transpose(X,-5) ,7) ) ) ) +(((((step(transpose(X,-7) ,12) +transpose(echo(step(transpose(X,4) ,12) ,4,6) ,4) ) +transpose((arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) |echo(transpose(X,-7) ,4,6) ) ,7) ) +transpose(transpose(echo(X,4,6) ,-7) ,12) ) +transpose(transpose((arpeggio((echo(X,4,6) |transpose(transpose(arpeggio(X) ,4) ,4) ) ) |transpose((((X+transpose(X,4) ) +transpose((X+X) ,7) ) |((X|X) +transpose(X,7) ) ) ,-5) ) ,-5) ,7) ) +transpose(transpose(transpose(((transpose(echo(X,4,6) ,4) +transpose(arpeggio((X|(X|X) ) ) ,4) ) +transpose((shuffle(step(step(X,12) ,12) ) +transpose(transpose((arpeggio(X) |X) ,4) ,12) ) ,7) ) ,4) ,-7) ,7) ) ) +transpose(shuffle((echo(((transpose(X,-5) +transpose(shuffle((echo(X,4,6) +(X|X) ) ) ,4) ) +transpose(transpose(shuffle((X+transpose(X,12) ) ) ,4) ,7) ) ,4,6) +transpose((shuffle(transpose((transpose(X,4) +X) ,4) ) +transpose(transpose((echo((X+X) ,4,6) +X) ,-5) ,4) ) ,12) ) ) ,7) ) ,-7) ,7) ) ,4) ,12)
random seed used was 0 EXPR = (transpose(((((transpose(echo(((transpose(X,-5) +transpose((((X+X) +transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose((X+X) ,7) ) ,4,6) ,-7) +(((transpose((X+X) ,-7) +(X+transpose(X,7) ) ) +((X+transpose(X,7) ) |(X+(X+transpose(X,7) ) ) ) ) |arpeggio(transpose(X,-5) ) ) ) +transpose(echo(step((X+echo(X,4,6) ) ,12) ,4,6) ,12) ) |(transpose(transpose((transpose(step(X,12) ,4) |((echo((transpose((X+transpose(X,7) ) ,4) |(X+transpose(X,7) ) ) ,4,6) +transpose((transpose((transpose(X,4) +arpeggio(X) ) ,4) +transpose(X,12) ) ,4) ) +transpose(transpose(((transpose(step(X,12) ,-7) +transpose(transpose(transpose(X,4) ,4) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4) ,7) ) ) ,-5) ,-7) |shuffle(transpose((arpeggio(transpose(X,4) ) +transpose(((arpeggio((X+X) ) +transpose(shuffle(echo(X,4,6) ) ,7) ) |transpose((X+transpose(X,4) ) ,-5) ) ,4) ) ,4) ) ) ) |(echo((((((transpose((arpeggio(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,4) +transpose((transpose(arpeggio(X) ,-7) |((X+X) +X) ) ,7) ) +transpose(arpeggio(transpose(transpose(X,4) ,-7) ) ,4) ) +transpose(transpose((X|X) ,4) ,7) ) +step(((((X+X) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) |transpose(X,-7) ) ,12) ) +transpose(((transpose(transpose((X|X) ,-5) ,-7) |arpeggio(arpeggio(X) ) ) +(transpose((X+transpose(echo(X,4,6) ,12) ) ,-7) +transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) |(arpeggio(echo(X,4,6) ) +transpose(shuffle((transpose(X,4) +transpose(X,7) ) ) ,7) ) ) ,12) ) ) ,12) ) ,4,6) +transpose((transpose(((((echo((X+transpose(X,7) ) ,4,6) +transpose(X,4) ) +transpose(arpeggio(X) ,7) ) +transpose(X,4) ) +transpose(transpose(transpose((X+transpose(X,12) ) ,-7) ,-7) ,7) ) ,4) |((transpose(arpeggio(X) ,4) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) |(transpose(step(X,12) ,-7) +transpose(shuffle(X) ,12) ) ) ) ,-7) ) ) ,-7) +transpose(((((transpose(transpose(((echo(X,4,6) +transpose((X+transpose(arpeggio(X) ,7) ) ,7) ) |shuffle((X|X) ) ) ,4) ,-5) +transpose(transpose(echo(transpose((transpose((X+transpose(transpose(X,-5) ,7) ) ,-5) +transpose((transpose((step(X,12) +step(X,12) ) ,-5) |transpose(((X+transpose(X,4) ) +transpose((X+X) ,7) ) ,-7) ) ,12) ) ,-7) ,4,6) ,4) ,12) ) +(((transpose(shuffle((transpose(X,-7) |transpose(shuffle(arpeggio(step(X,12) ) ) ,4) ) ) ,4) +transpose((transpose(transpose((transpose(transpose(X,4) ,-5) +transpose(transpose(X,-5) ,7) ) ,4) ,4) +echo(transpose(X,-5) ,4,6) ) ,4) ) +transpose((transpose(shuffle(transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,-5) ) ,-5) +transpose(transpose(shuffle((arpeggio(X) +transpose(step(transpose(X,4) ,12) ,12) ) ) ,4) ,-7) ) ,7) ) +transpose(shuffle((echo((((transpose(X,4) +transpose((X+transpose(X,12) ) ,4) ) +transpose((((X|X) +transpose(shuffle(X) ,4) ) +transpose(X,7) ) ,7) ) +transpose(arpeggio(echo((X|X) ,4,6) ) ,12) ) ,4,6) +transpose((transpose((arpeggio(X) +(X|X) ) ,4) +(echo(((X|X) +transpose(transpose(X,-7) ,12) ) ,4,6) |((X+transpose(echo(transpose((X|X) ,4) ,4,6) ,4) ) +transpose(step(((X+X) +(X+transpose(X,7) ) ) ,12) ,7) ) ) ) ,7) ) ) ,12) ) ) |(((transpose(transpose((transpose(X,-5) |X) ,-7) ,4) +(((((transpose(transpose(X,-5) ,4) +transpose(step(X,12) ,4) ) +transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,7) ) +transpose((step(((X|X) |transpose(X,-7) ) ,12) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) +transpose(transpose((transpose(transpose(X,4) ,4) |((X|X) +transpose(transpose(X,-5) ,7) ) ) ,4) ,4) ) +transpose(((X|transpose(X,4) ) |transpose((X+transpose(X,12) ) ,4) ) ,7) ) ) +transpose((echo(echo(transpose(transpose(X,-7) ,4) ,4,6) ,4,6) +transpose(transpose((X+X) ,4) ,7) ) ,12) ) +transpose(step((((transpose(transpose(((X+transpose(X,7) ) +transpose(X,-5) ) ,-5) ,-7) +transpose(transpose(shuffle((X+X) ) ,-7) ,7) ) |echo(shuffle((X+(X+X) ) ) ,4,6) ) +shuffle(transpose(transpose(echo(transpose((X|transpose(X,4) ) ,-5) ,4,6) ,-5) ,-5) ) ) ,12) ,7) ) ) +transpose(((((transpose(shuffle(arpeggio(arpeggio(transpose(X,4) ) ) ) ,-7) +(transpose((((X+X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4) |transpose((((X+X) +transpose(shuffle(X) ,12) ) +(echo(arpeggio(X) ,4,6) |step(transpose(X,-7) ,12) ) ) ,-7) ) ) +transpose(arpeggio((transpose(step(echo((X+X) ,4,6) ,12) ,-5) +(transpose(X,-5) +transpose(transpose(transpose(echo(X,4,6) ,4) ,-5) ,7) ) ) ) ,4) ) +transpose((transpose((X+transpose(X,4) ) ,4) +transpose((((shuffle(X) |transpose(X,-7) ) +transpose((X+transpose(X,7) ) ,12) ) +transpose(transpose(((X+(X+transpose(X,7) ) ) +(X+transpose(X,-7) ) ) ,4) ,7) ) ,7) ) ,7) ) +(transpose((step(echo(transpose(X,4) ,4,6) ,12) +transpose(shuffle(echo((echo(X,4,6) +(X+X) ) ,4,6) ) ,7) ) ,4) +(((((transpose(X,4) +echo((transpose(transpose(X,4) ,-7) +X) ,4,6) ) +transpose(((X+transpose(X,12) ) +transpose(transpose(X,-7) ,12) ) ,4) ) +transpose((transpose((X|transpose(X,4) ) ,4) +transpose((shuffle(X) +(transpose((X+X) ,-5) +transpose((((X+X) +transpose(X,4) ) +transpose(X,7) ) ,12) ) ) ,7) ) ,7) ) +transpose((transpose(shuffle(X) ,-7) +transpose(transpose((X+transpose(X,7) ) ,-7) ,12) ) ,12) ) +step(shuffle(step(transpose((transpose(X,4) +transpose(X,7) ) ,4) ,12) ) ,12) ) ) ) ,12) ) ,7) )
random seed used was 0

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