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 17 generations the expression "X" became this:
(transpose(step(transpose(transpose((step(transpose(transpose((((X+X) +transpose(shuffle((X+transpose(X,7) ) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,4) ,-5) ,12) |(transpose((transpose(step(X,12) ,-5) +transpose(((X+echo(X,4,6) ) +transpose(transpose(X,4) ,7) ) ,12) ) ,-7) |transpose((transpose(X,4) +transpose(transpose(X,-5) ,12) ) ,4) ) ) ,-5) ,-7) ,12) ,-5) |((transpose(transpose((((transpose(((X+transpose((X|X) ,7) ) +transpose(echo(X,4,6) ,4) ) ,-5) |(arpeggio(transpose((arpeggio(X) +transpose((X+X) ,7) ) ,4) ) +echo(shuffle((X+transpose(transpose(X,-5) ,12) ) ) ,4,6) ) ) |step((echo(((((X+transpose(shuffle(shuffle(X) ) ,7) ) +transpose(transpose(transpose(echo((X+transpose(X,12) ) ,4,6) ,-5) ,-5) ,12) ) +transpose(transpose(shuffle(shuffle(transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,-5) ) ) ,-7) ,4) ) +transpose(step(transpose(((((X+transpose(transpose(X,-7) ,12) ) +transpose(transpose((X|X) ,-5) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) +transpose((X+transpose(X,12) ) ,12) ) ,4) ,12) ,7) ) ,4,6) +(transpose((transpose(((transpose(X,4) +X) +transpose(transpose((X+transpose(X,7) ) ,-5) ,7) ) ,4) +transpose(transpose(step(step(X,12) ,12) ,-5) ,12) ) ,-7) |transpose((transpose(X,-7) +transpose(echo(transpose((X|X) ,4) ,4,6) ,7) ) ,-5) ) ) ,12) ) |step((transpose(transpose(transpose(echo(X,4,6) ,-5) ,4) ,4) +transpose(((transpose(transpose(((transpose((X|X) ,4) +transpose((X+transpose(((step(X,12) +transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) ,7) ) ,12) ) +transpose(echo(transpose(echo(X,4,6) ,-7) ,4,6) ,4) ) ,-5) ,4) +((echo(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,4,6) +transpose(step(((X+transpose(X,4) ) +transpose(transpose(X,4) ,7) ) ,12) ,12) ) |echo(step(X,12) ,4,6) ) ) +transpose(((transpose(transpose(transpose(echo(echo((X+X) ,4,6) ,4,6) ,-5) ,-5) ,-5) +transpose(((transpose(X,-5) |(((X|X) +transpose(X,12) ) +transpose((X+X) ,12) ) ) +(transpose(transpose((X+X) ,-5) ,4) +transpose(transpose(transpose(transpose(X,-5) ,-5) ,-7) ,7) ) ) ,4) ) +transpose(transpose(transpose(transpose(transpose(X,4) ,4) ,-7) ,-7) ,7) ) ,7) ) ,12) ) ,12) ) ,-5) ,4) +transpose((((shuffle(transpose(arpeggio(transpose((((shuffle(X) |(X+transpose(X,7) ) ) +transpose(((X+X) +(X+transpose(X,-7) ) ) ,4) ) +transpose(((transpose(X,-7) +arpeggio(X) ) |((X+transpose(X,12) ) +transpose(X,7) ) ) ,7) ) ,-5) ) ,-7) ) +(echo(arpeggio(transpose(((step((X+X) ,12) +transpose((shuffle(transpose(X,-7) ) |(X+transpose((X+transpose(X,12) ) ,12) ) ) ,4) ) +transpose(shuffle(((X+X) +echo(X,4,6) ) ) ,7) ) ,-7) ) ,4,6) +transpose(echo(transpose(((step((echo((X+X) ,4,6) +arpeggio(X) ) ,12) +transpose(transpose((echo(X,4,6) +transpose(echo(X,4,6) ,7) ) ,-5) ,7) ) |(arpeggio((arpeggio((transpose(X,-7) +transpose(transpose(X,4) ,12) ) ) |X) ) |(shuffle(X) +transpose((((transpose(X,-5) +X) +((X+transpose(X,7) ) +transpose(step(X,12) ,12) ) ) |(transpose(X,-7) |echo(shuffle((X+transpose(X,12) ) ) ,4,6) ) ) ,12) ) ) ) ,4) ,4,6) ,7) ) ) |echo(((step(transpose(arpeggio(transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +echo(X,4,6) ) +transpose(transpose(X,4) ,7) ) ,4) ) ,-7) ,12) |((transpose((step(transpose((X|X) ,-5) ,12) +shuffle(X) ) ,-5) +transpose((transpose(X,4) |shuffle(transpose(X,-5) ) ) ,7) ) |((transpose((transpose(((X+transpose(X,12) ) +transpose((X+transpose(X,7) ) ,7) ) ,-5) +transpose((((X+transpose(X,12) ) +transpose(transpose(transpose(X,4) ,-5) ,4) ) +transpose(transpose(step(X,12) ,-5) ,7) ) ,7) ) ,4) +transpose(transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(shuffle(X) ,12) ) |(echo(transpose((X+transpose(X,7) ) ,-7) ,4,6) |arpeggio(transpose(X,-7) ) ) ) ,4) ,12) ) +transpose((((shuffle(arpeggio(X) ) +transpose((transpose(X,4) +transpose(step(X,12) ,-5) ) ,4) ) +transpose(transpose(X,-5) ,7) ) +transpose(echo((X+X) ,4,6) ,12) ) ,4) ) ) ) |transpose(transpose((transpose(((X+transpose(X,7) ) +transpose(arpeggio(X) ,12) ) ,4) +X) ,-5) ,-7) ) ,4,6) ) +transpose(arpeggio(transpose(((shuffle(((((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) +transpose(echo(transpose(arpeggio(X) ,-5) ,4,6) ,4) ) ) +transpose(shuffle(X) ,12) ) +transpose(((transpose(echo(((((X+transpose(X,4) ) +transpose(X,7) ) +(X+transpose(X,12) ) ) +transpose(shuffle((X+transpose(X,7) ) ) ,12) ) ,4,6) ,-7) +transpose((shuffle(arpeggio(echo(X,4,6) ) ) +((step(X,12) +(X+X) ) |(echo(X,4,6) +transpose(((X+transpose(X,12) ) +X) ,12) ) ) ) ,4) ) +transpose(shuffle((transpose(X,4) +arpeggio(transpose(X,-7) ) ) ) ,7) ) ,12) ) ,-5) ) ,12) ) ,4) ) +transpose(((transpose((transpose(((transpose(((shuffle(X) +transpose(transpose(transpose(X,-7) ,4) ,4) ) +transpose(((X+X) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ,4) |arpeggio(shuffle(transpose(arpeggio(echo(X,4,6) ) ,4) ) ) ) |shuffle((step(transpose(step(transpose(transpose(X,-5) ,4) ,12) ,-7) ,12) |(shuffle(arpeggio(step(X,12) ) ) +shuffle(step(((arpeggio(X) |(X+X) ) +transpose((X+transpose(X,12) ) ,-7) ) ,12) ) ) ) ) ) ,4) |((arpeggio((((X+X) +transpose((transpose(X,-5) +transpose((X+transpose(X,12) ) ,12) ) ,7) ) |(transpose(X,-7) |transpose(X,-5) ) ) ) +transpose(transpose(transpose(transpose(transpose(((X+transpose((X+transpose(X,12) ) ,12) ) |X) ,4) ,-5) ,-7) ,-5) ,7) ) +transpose((arpeggio(step(transpose(shuffle((X|X) ) ,-7) ,12) ) +transpose(((X+transpose((X|X) ,7) ) +arpeggio((echo(X,4,6) |(transpose(transpose(X,-7) ,4) +transpose(transpose(X,4) ,12) ) ) ) ) ,-5) ) ,12) ) ) ,-7) +transpose(shuffle((((((transpose((X+X) ,4) +transpose(transpose(transpose(X,4) ,-5) ,12) ) +transpose(transpose((step(X,12) +(echo((X|X) ,4,6) +transpose((X+X) ,7) ) ) ,-5) ,4) ) +transpose(transpose(transpose((transpose(X,-5) +transpose(echo((X+transpose(X,12) ) ,4,6) ,7) ) ,-5) ,-7) ,7) ) +transpose(((step(((X+transpose(X,12) ) +X) ,12) +(step(transpose((X+X) ,-5) ,12) +transpose((step(transpose(X,-7) ,12) |echo(X,4,6) ) ,-7) ) ) +transpose((X+X) ,-7) ) ,4) ) +transpose(transpose((((shuffle((step(transpose(X,4) ,12) +transpose(X,-7) ) ) +transpose(((transpose(X,-7) +transpose(transpose(X,4) ,-5) ) +transpose(((X+transpose(transpose(X,-5) ,12) ) |(echo(transpose(X,-7) ,4,6) +(X+transpose(X,12) ) ) ) ,12) ) ,7) ) +transpose(arpeggio((step(echo(X,4,6) ,12) +transpose((echo(transpose(X,-7) ,4,6) +(X|X) ) ,12) ) ) ,4) ) +transpose((transpose(arpeggio((transpose(X,-7) |(X+X) ) ) ,-7) +transpose(transpose(arpeggio(step((shuffle((X|X) ) +transpose(((X|X) +transpose(X,-5) ) ,7) ) ,12) ) ,-5) ,12) ) ,7) ) ,4) ,7) ) ) ,12) ) |((transpose(transpose(((((((transpose((((X|(X|X) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose((X+transpose(shuffle(X) ,7) ) ,7) ) ,4) +transpose((step(X,12) +((X+transpose(X,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,12) ) +transpose(transpose(shuffle(transpose(transpose(X,-7) ,-5) ) ,-5) ,12) ) +transpose(transpose(((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +transpose(step(X,12) ,12) ) |((transpose(X,-7) |X) +transpose((X+transpose(X,7) ) ,-7) ) ) ,-7) ,12) ) |(transpose(X,-5) |step((((arpeggio((X+X) ) +transpose(((shuffle(X) +transpose(transpose(X,-5) ,4) ) +transpose(shuffle(X) ,7) ) ,4) ) +transpose((X+transpose(X,4) ) ,7) ) +transpose((transpose((X+transpose(X,7) ) ,4) +X) ,12) ) ,12) ) ) |((transpose((transpose(X,-7) +step(step(X,12) ,12) ) ,-5) |shuffle((arpeggio(X) |(((X+X) +transpose(X,-5) ) +((X|X) +(X+transpose(X,12) ) ) ) ) ) ) +transpose((transpose((transpose((X+(X|X) ) ,-5) +transpose((transpose(echo(transpose(X,-7) ,4,6) ,-5) +transpose(transpose(X,-7) ,-5) ) ,12) ) ,4) |transpose((X+((transpose(X,4) +transpose(X,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,-5) ) ,12) ) ) +transpose(echo(((transpose((X|(X+X) ) ,4) +((X+transpose(arpeggio(X) ,12) ) +shuffle(transpose(X,-7) ) ) ) |transpose((X|X) ,4) ) ,4,6) ,4) ) ,-5) ,-7) +transpose((((((transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-5) +(transpose(X,-5) +transpose(X,-5) ) ) +(((transpose((X|shuffle(X) ) ,-5) +transpose(arpeggio(transpose(X,4) ) ,4) ) +transpose(transpose(transpose(transpose(X,-7) ,-7) ,4) ,7) ) +transpose(((arpeggio(arpeggio(echo(X,4,6) ) ) +transpose((shuffle(echo(X,4,6) ) +transpose(step((X+arpeggio(X) ) ,12) ,7) ) ,12) ) |transpose(((X+transpose((X+X) ,4) ) +transpose(step(X,12) ,7) ) ,-7) ) ,12) ) ) +transpose(step((transpose((((transpose(arpeggio(X) ,-5) +arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ) +transpose(transpose(transpose(transpose(arpeggio(X) ,-7) ,-7) ,-5) ,4) ) +transpose(transpose(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-7) ,4) ,7) ) ,4) +arpeggio((transpose(X,4) +transpose(transpose((X+X) ,-5) ,7) ) ) ) ,12) ,7) ) |echo(((transpose((((transpose(X,-7) +transpose((transpose(X,-7) +transpose(step(X,12) ,7) ) ,12) ) +transpose(step(echo(X,4,6) ,12) ,4) ) +transpose(step(shuffle(X) ,12) ,7) ) ,-5) |((echo(transpose(X,-7) ,4,6) +(transpose(X,-5) |transpose(X,4) ) ) |transpose(transpose(((X|X) |(transpose(X,-7) +X) ) ,4) ,4) ) ) +transpose((echo(transpose(transpose((transpose(X,4) |transpose(X,4) ) ,-7) ,-5) ,4,6) +transpose(shuffle(echo(((X|X) +transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,7) ) ,4,6) ) ,-5) ) ,7) ) ,4,6) ) |transpose(transpose((transpose(transpose(step(X,12) ,-5) ,-7) +echo(arpeggio((transpose(transpose(X,-5) ,4) |X) ) ,4,6) ) ,-5) ,-5) ) ,4) ) +transpose((transpose(transpose(transpose(transpose((X|X) ,-7) ,-7) ,4) ,-5) +((transpose(arpeggio(transpose(transpose(X,-5) ,-5) ) ,-7) |transpose(echo((((X|((X+transpose(X,4) ) +transpose(X,7) ) ) |X) |((echo(X,4,6) +transpose(step(X,12) ,4) ) +transpose((echo(X,4,6) +transpose(transpose(X,-7) ,12) ) ,7) ) ) ,4,6) ,4) ) |echo(transpose(((X+transpose(X,12) ) +transpose(transpose((X+X) ,-7) ,7) ) ,4) ,4,6) ) ) ,7) ) ) ,7) ) )
random seed used was 230638793

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