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 14 generations the expression "X" became this:
(((((((arpeggio((((X+X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) |X) ) +transpose((((X+transpose(X,12) ) +(X+transpose(X,12) ) ) +transpose(transpose(((X+transpose(X,4) ) +transpose(shuffle(X) ,7) ) ,4) ,12) ) ,7) ) +transpose((transpose(transpose(X,4) ,-7) +transpose(arpeggio(transpose(X,-5) ) ,7) ) ,7) ) |(transpose(arpeggio(transpose(X,4) ) ,4) +transpose(transpose(echo((X+transpose(shuffle(transpose(X,4) ) ,7) ) ,4,6) ,4) ,12) ) ) |transpose((transpose((step((X+transpose(X,7) ) ,12) +echo((shuffle(X) |(X|X) ) ,4,6) ) ,4) +transpose(((echo(X,4,6) +transpose(X,4) ) +transpose((X+transpose(transpose(X,-7) ,12) ) ,4) ) ,12) ) ,-5) ) +transpose((transpose((((transpose(X,-5) +echo(transpose(transpose(X,4) ,-7) ,4,6) ) +transpose((arpeggio((X+transpose(X,7) ) ) +transpose(echo(transpose(transpose(X,-7) ,4) ,4,6) ,7) ) ,4) ) +transpose(((transpose(((X+transpose(X,12) ) +(X|X) ) ,-7) +transpose(echo(transpose((X+(X|X) ) ,-7) ,4,6) ,12) ) +transpose((shuffle(transpose((X+X) ,4) ) +transpose(transpose(echo((X|X) ,4,6) ,-7) ,7) ) ,12) ) ,7) ) ,-5) +transpose(((transpose(transpose(X,-7) ,4) +transpose(transpose(X,-5) ,-7) ) +transpose(shuffle(((arpeggio(transpose((X|X) ,-5) ) |(((X+transpose(transpose(transpose(X,4) ,4) ,4) ) +transpose(transpose((X+transpose(X,7) ) ,4) ,7) ) +((X+transpose(echo(X,4,6) ,7) ) +transpose((transpose(X,4) +(X+X) ) ,7) ) ) ) +transpose((X+transpose((X+X) ,12) ) ,7) ) ) ,7) ) ,7) ) ,4) ) +transpose(((transpose(((transpose(echo(transpose(X,-7) ,4,6) ,-5) +arpeggio(arpeggio(transpose(step(echo(X,4,6) ,12) ,4) ) ) ) |transpose((((X|X) |(((transpose(X,-5) +(X+transpose(X,7) ) ) +transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) ) +step(arpeggio(X) ,12) ) ,-5) ) ,-5) +transpose(((((((X|X) +transpose(arpeggio(X) ,12) ) +transpose(step(X,12) ,7) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) |transpose(transpose(transpose(X,-7) ,4) ,4) ) |shuffle(((transpose((echo(X,4,6) +transpose(X,-5) ) ,4) +transpose((transpose(transpose(X,4) ,-7) |(transpose(X,-7) +transpose(X,4) ) ) ,4) ) +transpose(transpose(transpose(transpose(transpose(X,-5) ,-5) ,-7) ,-7) ,7) ) ) ) ,12) ) +transpose(((transpose(echo(((echo(transpose(X,-7) ,4,6) +echo(((X+X) |(X+X) ) ,4,6) ) +transpose((transpose(X,4) +transpose(echo((transpose(X,4) +transpose((X+transpose(X,7) ) ,7) ) ,4,6) ,12) ) ,7) ) ,4,6) ,4) +transpose((((transpose((transpose(transpose(X,-5) ,-7) +transpose(X,-5) ) ,4) +transpose((((step((X+transpose(X,7) ) ,12) +transpose((X|X) ,-5) ) +transpose(transpose(((transpose(X,4) +transpose(X,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,-7) ,4) ) +transpose(transpose(transpose(shuffle(X) ,-5) ,-5) ,7) ) ,4) ) +transpose(transpose(transpose((((X+(X+transpose(X,7) ) ) +transpose(transpose(X,-5) ,4) ) +transpose(((X+X) +transpose(X,12) ) ,7) ) ,-7) ,4) ,7) ) +echo(((X+X) +transpose(X,7) ) ,4,6) ) ,12) ) +transpose(arpeggio(arpeggio(shuffle(transpose(X,-7) ) ) ) ,12) ) ,12) ) ,7) ) +transpose(transpose(transpose(transpose((((transpose((transpose(X,4) +arpeggio(echo(X,4,6) ) ) ,4) +transpose(transpose(((transpose(transpose((X+X) ,-5) ,-5) |transpose(transpose((X+X) ,-5) ,4) ) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ,4) ,12) ) +transpose(transpose(transpose((X+(transpose(((arpeggio(X) +transpose(X,4) ) +transpose((X|X) ,7) ) ,-7) +step(((X+transpose(X,7) ) |echo(X,4,6) ) ,12) ) ) ,-7) ,-7) ,4) ) +transpose((transpose(((transpose(X,-5) +(X|(X+transpose(X,12) ) ) ) +transpose((shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) |((X|X) +X) ) ,12) ) ,-7) +(transpose(transpose(step(X,12) ,4) ,-7) +transpose(transpose(arpeggio(arpeggio(X) ) ,4) ,7) ) ) ,7) ) ,-7) ,-7) ,-5) ,7) )
random seed used was 173411135 EXPR = ((((((((shuffle(transpose((shuffle((X+X) ) |echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ) ,-7) ) +transpose(transpose(transpose(transpose(transpose(X,4) ,4) ,4) ,-7) ,12) ) +transpose(echo(((echo(transpose(transpose(X,-7) ,-5) ,4,6) +transpose(arpeggio(transpose(X,-5) ) ,12) ) |shuffle(transpose((X+X) ,4) ) ) ,4,6) ,12) ) +transpose((((shuffle(shuffle(((step((arpeggio(step(X,12) ) |transpose(X,4) ) ,12) +transpose(transpose((arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) +X) ,-7) ,4) ) +transpose(transpose(transpose(transpose(X,4) ,-5) ,4) ,7) ) ) ) +transpose(((echo((X+transpose(transpose(((X+echo(X,4,6) ) |echo(X,4,6) ) ,-7) ,12) ) ,4,6) +transpose((shuffle(transpose(X,4) ) +transpose(transpose(transpose((step(X,12) +(transpose(X,4) |X) ) ,-7) ,4) ,12) ) ,4) ) +transpose(arpeggio(((transpose(transpose(X,-5) ,4) +((X+transpose(X,12) ) +transpose(X,7) ) ) +((X+transpose((X|transpose(X,-5) ) ,4) ) +transpose(echo((X+transpose(X,7) ) ,4,6) ,7) ) ) ) ,7) ) ,4) ) +transpose(transpose(step(transpose(transpose(transpose(X,-5) ,-5) ,-5) ,12) ,-7) ,7) ) +transpose(echo(transpose(transpose(X,4) ,4) ,4,6) ,4) ) ,4) ) +transpose(transpose((transpose(echo(transpose(echo(transpose(X,4) ,4,6) ,-5) ,4,6) ,-5) |((((transpose((X|X) ,-5) +transpose(shuffle(transpose(X,-5) ) ,4) ) +transpose((transpose(X,-7) |(X+transpose(transpose(X,-7) ,12) ) ) ,7) ) +transpose((transpose((transpose(X,-7) +transpose(X,7) ) ,-7) |step(step((X+X) ,12) ,12) ) ,4) ) +transpose(((echo((X+X) ,4,6) +transpose((((transpose(X,4) +transpose((echo(X,4,6) |X) ,12) ) +transpose(arpeggio((X+transpose(X,12) ) ) ,4) ) +transpose(shuffle(X) ,7) ) ,4) ) +transpose((arpeggio(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) |(X|X) ) ,7) ) ,7) ) ) ,4) ,7) ) |transpose(((arpeggio(arpeggio(transpose((X+transpose(transpose(X,4) ,12) ) ,-5) ) ) +transpose(step(((((X|(X+((X+transpose(X,4) ) +transpose(X,7) ) ) ) |(((transpose(X,-7) +transpose((X|X) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) |transpose(transpose(X,4) ,-7) ) ) |transpose(transpose(transpose(X,4) ,-7) ,-7) ) +transpose(step(transpose(X,-5) ,12) ,-7) ) ,12) ,4) ) +transpose((((transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,-7) +((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) +(echo(transpose(X,-5) ,4,6) +echo((X|X) ,4,6) ) ) |(((X+transpose(transpose(X,-5) ,4) ) +transpose((echo(X,4,6) +transpose((X+X) ,12) ) ,7) ) +transpose(arpeggio(X) ,7) ) ) ) +transpose(((transpose(X,-7) +transpose((transpose(X,4) |X) ,4) ) +transpose((((arpeggio(X) |arpeggio(X) ) +transpose(transpose(X,-5) ,7) ) +(transpose((X|X) ,-5) +transpose(shuffle(transpose(X,-5) ) ,7) ) ) ,7) ) ,4) ) +transpose((transpose(X,-7) +((((X|X) +transpose((X|X) ,4) ) +transpose((X|X) ,7) ) +transpose(X,4) ) ) ,7) ) ,7) ) ,4) ) +echo(((shuffle(((transpose(transpose((shuffle(X) +transpose(X,12) ) ,4) ,-5) |((X+transpose((X|X) ,4) ) +transpose(X,7) ) ) +transpose(shuffle((X+transpose((X+X) ,7) ) ) ,7) ) ) |(echo(arpeggio(((((X+transpose(X,4) ) +transpose(X,7) ) +X) +transpose(transpose((X+X) ,-7) ,12) ) ) ,4,6) |transpose((((X+transpose(X,7) ) |(((X+transpose(X,4) ) +transpose(X,7) ) |transpose(X,4) ) ) +transpose(shuffle(echo(shuffle(X) ,4,6) ) ,7) ) ,-7) ) ) +transpose((((transpose(X,-7) +echo(echo(X,4,6) ,4,6) ) |((((X+transpose(transpose(X,-7) ,12) ) +arpeggio(arpeggio(step(X,12) ) ) ) +transpose((transpose((X+X) ,-7) +transpose(echo((X+X) ,4,6) ,12) ) ,4) ) +transpose(((transpose((arpeggio(X) +transpose(transpose(X,-5) ,12) ) ,4) +transpose(echo(echo((X+transpose(echo(X,4,6) ,7) ) ,4,6) ,4,6) ,4) ) +transpose(((X+(X|X) ) |((X+transpose(transpose(arpeggio(X) ,-7) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ) ,7) ) ,7) ) ) |(step(echo(transpose(X,-5) ,4,6) ,12) +(shuffle(transpose(X,-7) ) |step(arpeggio((((arpeggio(X) +transpose(step(transpose(X,-5) ,12) ,4) ) +transpose(echo((X|X) ,4,6) ,7) ) +transpose(((step(X,12) +transpose((X|X) ,4) ) +transpose((transpose(X,4) +transpose(X,12) ) ,7) ) ,12) ) ) ,12) ) ) ) ,7) ) ,4,6) ) +transpose(((shuffle(transpose(step((arpeggio(transpose(transpose((X|X) ,-5) ,4) ) +arpeggio(((transpose(transpose(X,4) ,-7) +transpose(shuffle(X) ,7) ) +transpose(transpose(step(((X+transpose(X,7) ) +X) ,12) ,4) ,7) ) ) ) ,12) ,-5) ) |(transpose((transpose((transpose(transpose(X,-5) ,-7) +echo(step(X,12) ,4,6) ) ,4) |transpose((X|X) ,4) ) ,-5) |(transpose((((X+X) +(X+X) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ,4) +(transpose(step((X+transpose(X,7) ) ,12) ,4) +transpose(((X+transpose(((((X+transpose(X,7) ) |X) +transpose(((X+transpose(X,7) ) |transpose(X,4) ) ,7) ) +transpose((X+transpose(X,-5) ) ,7) ) ,7) ) +((((((X+transpose(X,4) ) +transpose(transpose(X,4) ,7) ) +(X+step(X,12) ) ) +transpose(((X+transpose(X,7) ) +transpose(X,12) ) ,4) ) +transpose(transpose(arpeggio(X) ,4) ,7) ) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+X) ,7) ) +transpose(step(X,12) ,7) ) ,7) ) ) ,7) ) ) ) ) |step(transpose((transpose((step(step(X,12) ,12) +transpose((arpeggio(X) +transpose(((X+transpose(X,12) ) +transpose(X,7) ) ,12) ) ,12) ) ,4) |((transpose(((transpose(X,4) |X) +transpose((transpose(X,-7) |(X+transpose(X,7) ) ) ,7) ) ,-5) +(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,-5) ) ) +(((transpose(X,-7) |(X+transpose(arpeggio(X) ,12) ) ) +transpose(transpose((transpose(X,4) +X) ,4) ,4) ) +transpose((((transpose(X,-5) +(X+X) ) +transpose((transpose(X,-5) |step(X,12) ) ,4) ) +transpose((((X+transpose(X,7) ) +transpose(step(X,12) ,4) ) +transpose(X,7) ) ,7) ) ,7) ) ) ) ,-5) ,12) ) ,7) ) |(((echo(transpose(transpose(echo(((step(X,12) +transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,4,6) ,-7) ,-7) ,4,6) +transpose((transpose((transpose(X,-7) |X) ,-5) |transpose(X,-7) ) ,12) ) |echo(((transpose(transpose((X+X) ,4) ,-5) +transpose(echo(arpeggio((X+X) ) ,4,6) ,7) ) +shuffle((transpose(X,-5) +transpose((shuffle(X) +(X+step(X,12) ) ) ,7) ) ) ) ,4,6) ) |transpose((transpose((((X|shuffle(X) ) +transpose(echo(X,4,6) ,4) ) +transpose(((X+transpose(transpose(X,4) ,4) ) +transpose((X|X) ,7) ) ,7) ) ,-5) |(((X+transpose(echo((X+arpeggio(X) ) ,4,6) ,12) ) +transpose((transpose(X,4) +transpose(arpeggio(transpose(X,-5) ) ,12) ) ,7) ) +transpose(transpose(((X|step(X,12) ) |((echo(X,4,6) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) ,-7) ,12) ) ) ,-7) ) )
random seed used was 0 EXPR = step(transpose(((transpose(((X+transpose(X,7) ) +transpose(transpose((X+transpose((X+X) ,7) ) ,4) ,12) ) ,-7) +arpeggio((transpose((X+transpose(X,12) ) ,-5) |step(transpose((arpeggio(X) +transpose(transpose((X+X) ,-5) ,12) ) ,-5) ,12) ) ) ) +transpose((transpose((((transpose((X+X) ,4) |transpose((X|X) ,-5) ) +transpose((transpose(X,-5) |transpose(transpose(X,-7) ,-5) ) ,4) ) +transpose(X,7) ) ,4) |((echo(X,4,6) +transpose(transpose(shuffle(transpose((step(X,12) +(X|X) ) ,-5) ) ,-7) ,4) ) +transpose(step(step(X,12) ,12) ,7) ) ) ,4) ) ,-7) ,12)
random seed used was 0 EXPR = ((((transpose(transpose(transpose(transpose(echo((step(X,12) |X) ,4,6) ,4) ,-5) ,-7) ,-5) +transpose((echo(step(((transpose(X,4) +X) +transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +shuffle(X) ) ,7) ) ,12) ,4,6) +transpose(step(transpose(step(transpose(transpose(X,-5) ,4) ,12) ,-5) ,12) ,7) ) ,7) ) +transpose(transpose(transpose(step(arpeggio(transpose((X+transpose(X,7) ) ,4) ) ,12) ,-7) ,-7) ,7) ) +transpose((arpeggio(transpose(step(shuffle(transpose(X,-5) ) ,12) ,4) ) +transpose((shuffle((step(transpose((((X|X) +transpose((X+transpose(X,12) ) ,7) ) +transpose(echo(X,4,6) ,7) ) ,-7) ,12) |transpose((step(X,12) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,12) ) ,4) ) ) +transpose(shuffle((transpose(transpose((transpose(((X+X) |X) ,-7) |((X+transpose(X,12) ) |((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,-5) ,4) +transpose(transpose((step(step(X,12) ,12) |transpose(shuffle(X) ,4) ) ,-5) ,-7) ) ) ,7) ) ,7) ) ,4) ) +transpose((echo(((transpose(arpeggio(step(transpose(echo(transpose(X,4) ,4,6) ,4) ,12) ) ,4) +transpose((transpose((X+transpose(step(X,12) ,7) ) ,4) +transpose(transpose((X+transpose(transpose(X,-7) ,7) ) ,4) ,-5) ) ,12) ) +(((transpose(echo(X,4,6) ,-7) +arpeggio(step(X,12) ) ) +arpeggio((shuffle(step(X,12) ) +transpose(transpose((X+transpose(X,7) ) ,-5) ,7) ) ) ) |shuffle(((X+X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ) ) ,4,6) |(transpose(transpose((((X+transpose((X+transpose(X,7) ) ,4) ) +transpose(echo(X,4,6) ,7) ) +transpose(X,7) ) ,-7) ,4) +transpose(shuffle(((transpose(transpose(shuffle((X|X) ) ,-7) ,4) +transpose((X+X) ,-5) ) |echo(((((arpeggio(arpeggio(X) ) |((X+transpose(X,4) ) +transpose(X,7) ) ) +transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,-5) ) +transpose(transpose(echo((X|X) ,4,6) ,-5) ,4) ) +transpose((X+transpose(echo(echo(X,4,6) ,4,6) ,7) ) ,7) ) ,4,6) ) ) ,4) ) ) ,7) )
random seed used was 0

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