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 20 generations the expression "X" became this:
step(((transpose((transpose(transpose(transpose((((transpose(transpose(X,4) ,-5) +((step(transpose(X,4) ,12) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,4) ,-7) ) ) +transpose(transpose(transpose((X+transpose(X,7) ) ,-7) ,-5) ,7) ) +(((transpose(X,-5) |transpose(X,4) ) +transpose(transpose((transpose(X,-5) +transpose(X,7) ) ,-7) ,7) ) +transpose(shuffle(step((((transpose(X,4) +transpose(X,7) ) |shuffle(X) ) +(X|transpose(X,-5) ) ) ,12) ) ,7) ) ) ,-5) ,-7) ,4) +transpose((transpose(transpose(transpose((arpeggio(transpose((arpeggio(X) |(shuffle(X) +X) ) ,-5) ) |((step((transpose(transpose(X,-5) ,4) +transpose(((echo((transpose(X,-7) +X) ,4,6) +transpose(((X+transpose(transpose(X,-5) ,7) ) +(X+X) ) ,4) ) +transpose((X+transpose(transpose(X,-7) ,12) ) ,7) ) ,7) ) ,12) +shuffle(arpeggio(shuffle(transpose(X,-7) ) ) ) ) +transpose(echo(step((echo(transpose(X,4) ,4,6) +transpose(((((X+transpose(X,7) ) +(X|X) ) |X) +transpose((transpose((X+transpose(X,12) ) ,-5) +transpose((((X|X) +transpose(X,4) ) +transpose((X|X) ,7) ) ,12) ) ,7) ) ,12) ) ,12) ,4,6) ,7) ) ) ,-5) ,4) ,-5) +transpose(arpeggio(((transpose(transpose(((transpose((transpose((X+transpose(X,12) ) ,-7) +transpose((X+X) ,12) ) ,-7) +transpose(transpose((arpeggio((X+X) ) +arpeggio(transpose(X,-7) ) ) ,-7) ,4) ) +transpose(step(transpose(X,-5) ,12) ,7) ) ,-7) ,-5) +shuffle(step(((((X+X) +transpose(X,-7) ) +(((X+(transpose(X,4) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) +transpose(transpose(echo(transpose(X,-7) ,4,6) ,-5) ,12) ) +echo((shuffle(X) +transpose(X,12) ) ,4,6) ) ) +transpose(transpose(transpose(X,-5) ,4) ,-7) ) ,12) ) ) +((echo(echo(transpose(arpeggio(echo(transpose(shuffle((X+X) ) ,4) ,4,6) ) ,4) ,4,6) ,4,6) +transpose((transpose(((transpose(transpose((transpose(X,-5) +transpose((X+X) ,12) ) ,-5) ,-5) +transpose(echo(step(transpose(transpose(X,4) ,4) ,12) ,4,6) ,7) ) |shuffle((step((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +transpose((X+(X+transpose(X,12) ) ) ,7) ) ,12) +transpose((((X+X) +(transpose(X,4) +transpose(X,12) ) ) |transpose((X|X) ,-7) ) ,7) ) ) ) ,-7) +transpose(shuffle(step((((shuffle(X) +X) |shuffle(((step((X|X) ,12) +transpose(arpeggio((X+transpose(X,12) ) ) ,12) ) +transpose(transpose((((X+transpose(X,12) ) +transpose(X,4) ) +transpose(X,7) ) ,-7) ,12) ) ) ) |((transpose(X,4) +transpose(X,12) ) +(shuffle((X|transpose(X,-7) ) ) +transpose(((X+X) |(X+transpose(X,12) ) ) ,-7) ) ) ) ,12) ) ,12) ) ,4) ) +transpose((shuffle(X) +transpose(transpose(X,-5) ,12) ) ,7) ) ) ) ,7) ) ,7) ) ,-5) +transpose(transpose(transpose(transpose(arpeggio(transpose(step((transpose(((step(transpose(X,4) ,12) +transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,-7) +(transpose(echo(X,4,6) ,-5) +X) ) ,12) ,4) ) ,4) ,-5) ,-5) ,-7) ) |(((transpose((transpose(transpose((((((step(X,12) +transpose((transpose(X,-7) +transpose(X,12) ) ,4) ) +transpose((X+transpose((X+X) ,12) ) ,7) ) +((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose((X+transpose(X,7) ) ,-5) ) ) +transpose(echo(transpose((X+transpose(transpose(X,-5) ,12) ) ,-5) ,4,6) ,12) ) |((transpose((X+transpose(X,-5) ) ,4) +transpose(transpose(transpose((X|X) ,4) ,-5) ,4) ) +transpose(transpose(transpose(arpeggio(X) ,-7) ,4) ,7) ) ) ,4) ,4) +(transpose(((arpeggio(arpeggio(X) ) +transpose(transpose(arpeggio(X) ,4) ,12) ) +(X|X) ) ,-7) |transpose(transpose((X|X) ,4) ,4) ) ) ,4) +transpose(((transpose(((echo((((X|X) +transpose((X|(X+X) ) ,12) ) +transpose(step(step(X,12) ,12) ,7) ) ,4,6) +arpeggio(((X+transpose((X+transpose(echo(X,4,6) ,7) ) ,12) ) +transpose((transpose(arpeggio(step(X,12) ) ,-5) +(((X|X) |shuffle(X) ) +transpose(echo(X,4,6) ,7) ) ) ,7) ) ) ) +transpose((((step((shuffle(X) |echo((X+transpose(X,12) ) ,4,6) ) ,12) +((arpeggio(X) +transpose((transpose(X,-5) |step((X+transpose(X,12) ) ,12) ) ,4) ) +transpose(transpose(((X+transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) ,4) ,7) ) ) +((arpeggio((transpose(X,-5) +transpose((X+transpose(X,12) ) ,12) ) ) +transpose(((echo(transpose(X,-7) ,4,6) +transpose(echo((X+shuffle(X) ) ,4,6) ,4) ) +transpose(step((X+X) ,12) ,7) ) ,4) ) +transpose(transpose((X+transpose((X+X) ,12) ) ,-5) ,7) ) ) |((echo((X+transpose(X,7) ) ,4,6) +transpose(arpeggio((X+(X|X) ) ) ,4) ) +transpose(transpose(transpose((X+transpose(X,12) ) ,-5) ,-7) ,7) ) ) ,-7) ) ,4) +transpose(transpose((transpose(transpose(transpose(transpose(transpose(X,4) ,4) ,-5) ,4) ,-5) +transpose((echo((transpose(X,4) +transpose((step(X,12) |(X+transpose(X,12) ) ) ,7) ) ,4,6) +transpose(((transpose(X,4) +transpose(transpose(transpose(X,-5) ,-7) ,4) ) +transpose(transpose(((X|(X+transpose(X,-7) ) ) |transpose(step(X,12) ,4) ) ,-5) ,7) ) ,7) ) ,7) ) ,-7) ,4) ) +transpose(((transpose(transpose(step((X|(X+transpose(X,12) ) ) ,12) ,-5) ,-7) +transpose(step(transpose(transpose(transpose(arpeggio(X) ,-5) ,4) ,-7) ,12) ,-5) ) +transpose(((transpose(arpeggio(transpose(X,4) ) ,4) +transpose(transpose(((step(X,12) |X) +transpose(arpeggio((X+X) ) ,12) ) ,-7) ,12) ) +((echo((X+X) ,4,6) +transpose(((((((transpose(X,4) |(X+transpose(X,12) ) ) +transpose(((X+X) +transpose(X,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) +transpose(X,-5) ) +transpose((transpose(X,4) |step(arpeggio(X) ,12) ) ,4) ) +transpose(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,4) ,7) ) ,4) ) +transpose(transpose((((X+transpose(X,7) ) +transpose((X+X) ,12) ) +transpose(X,7) ) ,-7) ,7) ) ) ,7) ) ,7) ) ,4) ) +transpose((shuffle(echo((echo(transpose(transpose(X,-5) ,4) ,4,6) +shuffle(shuffle((transpose(shuffle(X) ,-5) +transpose(arpeggio(transpose(step(X,12) ,-5) ) ,7) ) ) ) ) ,4,6) ) +echo(transpose(arpeggio((echo((echo((X|X) ,4,6) +transpose((transpose(X,-7) +X) ,12) ) ,4,6) |arpeggio(transpose(shuffle(step(X,12) ) ,4) ) ) ) ,-5) ,4,6) ) ,7) ) |transpose((((arpeggio((step(step(transpose(((transpose(((X|X) |echo(arpeggio(X) ,4,6) ) ,4) +transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(transpose(X,4) ,-5) ,7) ) ,4) ,7) ) +echo(X,4,6) ) ,4) ,12) ,12) +transpose((((step(((((echo(X,4,6) |step(X,12) ) +transpose((transpose(X,4) +transpose((X|X) ,12) ) ,-7) ) +transpose(transpose((shuffle((X+X) ) +(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ) ,-7) ,4) ) +transpose(transpose((transpose(echo(step(X,12) ,4,6) ,4) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,12) ) ,4) ,7) ) ,12) +transpose((echo(transpose((shuffle((X+X) ) |(X+transpose(X,12) ) ) ,4) ,4,6) +transpose(step(transpose((((step(X,12) |X) +transpose((transpose(X,-7) +transpose((X+transpose(X,7) ) ,12) ) ,4) ) +transpose((X+X) ,7) ) ,-7) ,12) ,7) ) ,4) ) +transpose((transpose(arpeggio((transpose(X,-5) |X) ) ,4) +shuffle(((X+transpose(arpeggio(X) ,7) ) |(((X+transpose(X,4) ) +transpose(X,7) ) |transpose(X,-7) ) ) ) ) ,7) ) +transpose(((step(((X|(X+X) ) +transpose(shuffle(((X+transpose(X,4) ) +transpose((X+X) ,7) ) ) ,7) ) ,12) +transpose(step((((transpose(transpose(echo(X,4,6) ,-7) ,4) +transpose(shuffle(transpose(X,-7) ) ,4) ) +transpose(((X|X) +transpose((X|X) ,-5) ) ,7) ) |(echo((X+transpose(X,7) ) ,4,6) |(X+transpose((X|X) ,12) ) ) ) ,12) ,4) ) +transpose((arpeggio((((((arpeggio(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) +transpose(transpose(transpose(X,-7) ,-7) ,12) ) +transpose(shuffle(X) ,12) ) +transpose(transpose(transpose(X,-5) ,4) ,4) ) +transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) |X) ,-5) ,7) ) ) |(((transpose(transpose(X,-7) ,4) |shuffle(shuffle(X) ) ) |(((X+X) +(X+X) ) +transpose(transpose((X+transpose(X,7) ) ,-5) ,7) ) ) +transpose(transpose((transpose(transpose(shuffle(X) ,4) ,-5) +transpose((transpose((X+transpose((X+transpose(X,12) ) ,7) ) ,-5) |transpose(transpose(transpose(X,4) ,4) ,-7) ) ,7) ) ,-7) ,12) ) ) ,7) ) ,7) ) ,12) ) ) +transpose(transpose(((((((((transpose(shuffle(X) ,-7) +transpose((transpose(transpose(shuffle((X|X) ) ,4) ,-7) +transpose(transpose(((step(X,12) +transpose(((X+transpose(X,12) ) +transpose((X+transpose(X,7) ) ,7) ) ,4) ) +transpose((transpose(X,-5) +transpose(X,-5) ) ,7) ) ,-7) ,7) ) ,4) ) +transpose(transpose((((transpose(X,4) +transpose(transpose(X,4) ,7) ) +transpose(transpose((X|X) ,4) ,4) ) +transpose(transpose(transpose((X+X) ,-5) ,-5) ,7) ) ,-7) ,7) ) +transpose(echo(((echo(X,4,6) +step(X,12) ) +(transpose(arpeggio(arpeggio(X) ) ,4) |step(transpose(X,-5) ,12) ) ) ,4,6) ,4) ) +transpose(step(echo(transpose((((transpose((X+X) ,4) +transpose(((X+X) +(X+transpose(X,7) ) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) +((X+X) +transpose(X,7) ) ) ,-7) ,4,6) ,12) ,7) ) +transpose(step(shuffle((((shuffle((X|X) ) +transpose(transpose(((transpose(X,4) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+X) ,7) ) ,-7) ,12) ) |(arpeggio(X) +X) ) +(transpose((echo(transpose(X,-7) ,4,6) |transpose(transpose((X+transpose(X,7) ) ,4) ,-7) ) ,4) |(arpeggio(transpose((X|((X+transpose(X,7) ) |(X|X) ) ) ,4) ) +(transpose(transpose(((X+transpose(X,7) ) +X) ,-5) ,4) +transpose(arpeggio(((((X+X) +transpose(transpose(X,-7) ,12) ) +transpose(X,4) ) +transpose(X,7) ) ) ,7) ) ) ) ) ) ,12) ,4) ) +transpose(step(((step(transpose(((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) +transpose((X+X) ,4) ) +transpose((X+transpose(transpose(X,-5) ,7) ) ,7) ) ,4) ,12) |transpose(transpose(((X|step(X,12) ) |(X+X) ) ,4) ,-5) ) |step(((X+transpose(X,7) ) +(X+X) ) ,12) ) ,12) ,7) ) +transpose(((transpose(step(((((X+transpose(X,12) ) |transpose(echo(X,4,6) ,4) ) +transpose(((((X|(X+X) ) |((X+transpose(X,12) ) +transpose((echo(X,4,6) |(X+X) ) ,7) ) ) +transpose((shuffle((transpose(X,-7) |arpeggio(X) ) ) +((transpose(X,-7) +transpose((X|X) ,4) ) +transpose(echo(X,4,6) ,7) ) ) ,4) ) +transpose((X+transpose(((echo(X,4,6) +transpose(X,12) ) |echo(X,4,6) ) ,7) ) ,7) ) ,4) ) +transpose((echo(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) ,-5) ,4,6) +transpose(shuffle(transpose(X,-5) ) ,12) ) ,7) ) ,12) ,-7) +(shuffle(transpose(transpose((X+transpose(transpose(X,-7) ,12) ) ,-7) ,-7) ) +transpose((transpose((arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) |X) ,-5) +(transpose(transpose(X,-7) ,-7) +(transpose(transpose(X,-7) ,4) +(X+X) ) ) ) ,12) ) ) +(((transpose(echo(X,4,6) ,-5) +arpeggio(arpeggio((X+X) ) ) ) +arpeggio((((X+transpose(X,12) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(transpose(transpose(X,4) ,4) ,7) ) ) ) +transpose(echo(shuffle((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+transpose(X,7) ) ,4) ) +transpose(X,7) ) |(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) +(X+transpose(X,7) ) ) ) ) ,4,6) ,-5) ) ) ,4) ) +transpose(((shuffle(transpose(shuffle((shuffle((((X+X) +transpose(X,12) ) |arpeggio(X) ) ) |((transpose(X,-5) +transpose((X+(X+X) ) ,4) ) +transpose((X|step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ,7) ) ) ) ,-7) ) |step((transpose(transpose(X,-7) ,-7) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,12) ) ,12) ) +transpose((((((X|X) +transpose((step((X|X) ,12) |(((arpeggio(X) +transpose(X,7) ) +(transpose(X,-7) +X) ) |echo(echo(X,4,6) ,4,6) ) ) ,7) ) |transpose(transpose(((X+X) +transpose(X,7) ) ,4) ,-5) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) |(X|X) ) ,-5) ) +transpose((((transpose(((X+transpose((X+X) ,4) ) +transpose(transpose(X,4) ,7) ) ,-7) +(((((X+transpose(X,4) ) +transpose(X,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(arpeggio(transpose(X,-5) ) ,4) ) +transpose((step(X,12) +step(X,12) ) ,7) ) ) +transpose(step((X+(transpose(shuffle(X) ,-7) +((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,12) ,7) ) +echo((((X+transpose(X,7) ) +(transpose(X,-7) +(X+X) ) ) |(transpose(X,-7) |((X|X) +transpose(X,12) ) ) ) ,4,6) ) ,12) ) ,7) ) ,7) ) ,-5) ,4) ) +transpose(arpeggio((((((X|X) +step(transpose((X|X) ,-5) ,12) ) +transpose((step(((transpose(transpose(X,4) ,4) +transpose(transpose(arpeggio(X) ,-5) ,4) ) +transpose(shuffle(X) ,7) ) ,12) |transpose(transpose(X,-7) ,4) ) ,7) ) +transpose(((echo(transpose(((((X|X) |(X+X) ) +((shuffle(transpose(X,-7) ) +transpose(step((X|echo(X,4,6) ) ,12) ,12) ) +transpose(((echo((X|X) ,4,6) +transpose(echo(X,4,6) ,4) ) +transpose((transpose(X,-5) +transpose(X,12) ) ,7) ) ,7) ) ) +transpose((transpose(transpose(X,4) ,-5) +arpeggio(echo(arpeggio((X+X) ) ,4,6) ) ) ,12) ) ,-7) ,4,6) +transpose(((((transpose(step(X,12) ,-5) |((X+X) +transpose(transpose(X,4) ,12) ) ) +transpose(transpose(((arpeggio(X) +transpose((X+transpose((X+transpose(X,7) ) ,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) ,-7) ,-7) ) +transpose((transpose(shuffle(echo(transpose(X,-5) ,4,6) ) ,4) +transpose((((X|arpeggio(transpose(X,-7) ) ) |transpose(transpose(X,-5) ,-5) ) +transpose(transpose(transpose((X+transpose((X|X) ,7) ) ,-5) ,4) ,12) ) ,7) ) ,7) ) +transpose((transpose(((transpose(transpose(X,-7) ,-5) +transpose(transpose(X,-7) ,4) ) +transpose(((X|X) +transpose(X,12) ) ,7) ) ,-7) +transpose((transpose(arpeggio(X) ,-7) +transpose(((step(X,12) +transpose(transpose(X,4) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) ,7) ) ,12) ) ,4) ) +transpose(arpeggio((transpose(transpose(shuffle((transpose(X,4) +transpose(transpose(X,-7) ,7) ) ) ,-7) ,-7) |step(transpose(step((X|X) ,12) ,-7) ,12) ) ) ,7) ) ,7) ) |transpose(((transpose(arpeggio((shuffle((transpose(X,4) +(transpose(X,4) +X) ) ) |step(transpose(transpose(X,-7) ,-5) ,12) ) ) ,-7) +transpose((echo((((((X|X) |X) +(X|(X+X) ) ) +transpose((((((X|X) |X) +transpose(transpose(X,4) ,7) ) +transpose(transpose(((X+transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) ,4) ,4) ) +transpose((X|(arpeggio(X) +transpose(X,-7) ) ) ,7) ) ,7) ) +transpose(transpose((transpose(transpose(arpeggio(X) ,-7) ,4) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ,-5) ,7) ) ,4,6) |(((transpose(shuffle(X) ,4) +transpose(X,7) ) +transpose(transpose((X+transpose((X|X) ,7) ) ,-7) ,4) ) +transpose((((X|(X+X) ) |shuffle(arpeggio(X) ) ) +shuffle(X) ) ,7) ) ) ,4) ) +transpose(shuffle(transpose((transpose(X,4) +((echo(X,4,6) +transpose(transpose(X,4) ,7) ) +transpose(transpose(transpose(X,4) ,-5) ,12) ) ) ,-5) ) ,7) ) ,-5) ) ) ,7) ) +transpose(echo(step(transpose(step(transpose(step((((shuffle(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) +transpose(transpose(transpose(step(arpeggio(X) ,12) ,-7) ,-7) ,4) ) +transpose(transpose(transpose(transpose((X|X) ,-5) ,4) ,-5) ,7) ) ,12) ,-7) ,12) ,-5) ,12) ,4,6) ,12) ) ,-7) ) ) ,12)
random seed used was 167283874

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