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: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Phrase for X: Basic 1 - c,e,gBasic 2 - c,g,e,b-Basic 3 - c,gBasic 4 - cBasic 5 - co3,co4,co3,co2Chord 1 - c e gChord 2 - c e- gChord 3 - c e- g b-Chord 4 - c f gFile 1 - bachinv1.midFile 2 - bachinv2.midFile 3 - bachinv3.midFile 4 - bachinv4.midFile 5 - bachinv5.midFile 6 - bachinv6.midFile 7 - bachinv7.midFile 8 - bachinv8.mid # of Tracks: 1234 Randomize patches: noyes 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 theTune Trove! See what's alreadyin the Tune Trove!

 After 20 generations the expression "X" became this: (arpeggio((transpose(echo(step(((shuffle(step(transpose(transpose(transpose((X|(X+transpose(X,7) ) ) ,4) ,-5) ,-5) ,12) ) +transpose(transpose(transpose(step(X,12) ,-5) ,4) ,4) ) +transpose(((arpeggio(X) +((transpose((step(X,12) |X) ,-5) +transpose((transpose(X,-5) |transpose(X,-7) ) ,12) ) +transpose(transpose(transpose((X+X) ,-7) ,-5) ,7) ) ) +transpose(step(arpeggio(transpose(((step(transpose(transpose(X,-7) ,-5) ,12) +transpose(transpose(echo(X,4,6) ,4) ,4) ) +transpose(transpose(shuffle(X) ,-7) ,7) ) ,-5) ) ,12) ,7) ) ,7) ) ,12) ,4,6) ,4) +(transpose(transpose(transpose((transpose(X,-5) +transpose(((transpose(transpose(shuffle(X) ,-7) ,4) +shuffle((X+transpose(X,7) ) ) ) |transpose(transpose(((transpose(transpose(X,-7) ,4) +transpose((shuffle(X) |(X+X) ) ,4) ) +transpose(transpose(echo(X,4,6) ,-5) ,7) ) ,-5) ,-7) ) ,-7) ) ,-5) ,4) ,-7) |(transpose(((transpose(transpose(transpose(step(transpose(X,4) ,12) ,-7) ,-7) ,-5) +transpose((arpeggio(((arpeggio(echo(arpeggio(X) ,4,6) ) +transpose((X+transpose(shuffle(transpose(X,4) ) ,12) ) ,4) ) +transpose(transpose(transpose(X,-5) ,-7) ,7) ) ) +((echo(echo(shuffle((((shuffle(X) +transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) +transpose(((X|X) |(X+X) ) ,7) ) ) ,4,6) ,4,6) +transpose(echo(((((X+X) |arpeggio(X) ) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ,7) ) |step(X,12) ) ,4,6) ,4) ) +transpose(step((transpose(transpose((X+transpose(X,12) ) ,-7) ,4) |(((transpose(X,-5) +(X+transpose(X,12) ) ) +transpose((X+transpose((transpose(X,-7) +transpose((X+X) ,12) ) ,7) ) ,4) ) +transpose((echo(echo(X,4,6) ,4,6) +X) ,7) ) ) ,12) ,7) ) ) ,4) ) +transpose((step(arpeggio(transpose(transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) ,4) ,-7) ) ,12) +transpose(transpose(transpose(transpose(X,-7) ,4) ,-5) ,7) ) ,7) ) ,-7) +transpose((transpose(transpose((echo(transpose((transpose((X+transpose(X,7) ) ,-7) +transpose(transpose(X,-7) ,7) ) ,-7) ,4,6) +transpose((echo(transpose(((transpose(X,-7) +transpose(step(X,12) ,4) ) +transpose(shuffle((X|X) ) ,7) ) ,4) ,4,6) +transpose((((((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) |(((X+transpose(X,7) ) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ) |transpose(transpose(step(X,12) ,-5) ,-7) ) +transpose((((transpose(echo(X,4,6) ,-7) |(shuffle(X) +(X+transpose(X,7) ) ) ) |(transpose(shuffle(X) ,-7) +transpose(echo(X,4,6) ,7) ) ) |echo(X,4,6) ) ,4) ) +transpose(((shuffle(X) +transpose(step(transpose(transpose(X,-7) ,-5) ,12) ,4) ) +transpose(transpose(transpose((X|X) ,4) ,-5) ,7) ) ,7) ) ,7) ) ,7) ) ,4) ,-7) +transpose(arpeggio(transpose(echo(((X+transpose(X,7) ) +transpose((arpeggio(echo(X,4,6) ) +transpose(transpose(arpeggio(X) ,-7) ,12) ) ,7) ) ,4,6) ,-5) ) ,12) ) ,12) ) ) ) ) |shuffle(((((transpose(transpose(transpose((((transpose(X,4) +transpose(step((transpose(transpose(transpose((X|X) ,-7) ,-5) ,-5) +transpose((X|transpose(transpose(X,-5) ,-5) ) ,12) ) ,12) ,4) ) +transpose(arpeggio((arpeggio(X) |transpose(transpose(X,-7) ,-5) ) ) ,7) ) +arpeggio(((echo((X|X) ,4,6) |transpose((shuffle((X|X) ) |((X+transpose(X,4) ) +transpose((X|X) ,7) ) ) ,-7) ) |((arpeggio(transpose(X,-7) ) +transpose((transpose(X,-7) +transpose((transpose(X,4) |transpose(X,4) ) ,7) ) ,4) ) +transpose(transpose(((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +transpose(transpose((X+transpose(X,7) ) ,-7) ,4) ) +transpose(X,7) ) ,-5) ,7) ) ) ) ) ,4) ,-5) ,4) +transpose(((transpose(transpose(((((X+X) +transpose(((arpeggio(X) +transpose(X,4) ) +transpose(X,7) ) ,7) ) +(((transpose(X,4) +transpose(X,7) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ) +transpose((transpose((X+X) ,-5) |transpose((arpeggio(X) |X) ,-7) ) ,7) ) ,4) ,-7) |echo((((transpose(transpose((X|X) ,-5) ,-7) |transpose((transpose(X,4) +transpose(arpeggio(transpose((X|X) ,-5) ) ,7) ) ,-5) ) +transpose(arpeggio((arpeggio(((((X|X) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) +transpose(step((X+transpose(X,12) ) ,12) ,12) ) ) |arpeggio(arpeggio(shuffle(X) ) ) ) ) ,4) ) +transpose(transpose((shuffle(X) |transpose(((transpose(X,-5) +transpose(X,4) ) +transpose(step(X,12) ,7) ) ,-7) ) ,-7) ,7) ) ,4,6) ) |step(transpose(((((transpose(X,-7) |transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ) +transpose(arpeggio(arpeggio((X+transpose(X,7) ) ) ) ,7) ) +transpose(((((X+transpose(X,7) ) +transpose(transpose(X,4) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) +transpose(((X|X) +transpose((X|X) ,12) ) ,12) ) ,7) ) +transpose(transpose((step(X,12) +transpose(transpose(((X+transpose(X,12) ) +transpose((transpose(X,4) +transpose(X,4) ) ,7) ) ,-5) ,7) ) ,-5) ,12) ) ,4) ,12) ) ,4) ) +transpose(arpeggio(transpose(transpose(transpose((X+transpose(X,7) ) ,4) ,-7) ,-5) ) ,7) ) +transpose(arpeggio((step((shuffle(shuffle(transpose(step(((echo((((transpose(X,-5) +transpose(X,7) ) +transpose(transpose(X,-7) ,4) ) +transpose(step(X,12) ,7) ) ,4,6) +transpose(X,4) ) +transpose(step(arpeggio(X) ,12) ,7) ) ,12) ,-7) ) ) +transpose(transpose((((((X+transpose(arpeggio(X) ,12) ) +transpose((X+transpose(X,7) ) ,12) ) +transpose(((transpose(X,-5) +transpose(transpose(X,-5) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) +transpose(transpose((((X|X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,-5) ,4) ) +transpose(transpose(((X+transpose(X,12) ) |((X+transpose(X,7) ) |step(X,12) ) ) ,-7) ,7) ) ,-7) ,12) ) ,12) +transpose(((transpose(step(((transpose(X,4) |transpose((X+transpose(X,12) ) ,-5) ) |(echo(X,4,6) +transpose((X|transpose(X,4) ) ,7) ) ) ,12) ,4) |transpose(((step(transpose(X,-7) ,12) |shuffle(X) ) |step(arpeggio(arpeggio(X) ) ,12) ) ,-7) ) +transpose(((transpose((step((step((arpeggio(X) +X) ,12) +transpose(((X+transpose(transpose(X,4) ,7) ) +transpose(X,7) ) ,12) ) ,12) +transpose(echo(((((X+transpose(X,12) ) |transpose(X,-5) ) +transpose(X,4) ) +transpose((X|X) ,7) ) ,4,6) ,7) ) ,-5) +transpose(((transpose(((((((X+X) +transpose(step(X,12) ,12) ) +transpose(X,4) ) +transpose((X+transpose(X,7) ) ,7) ) |transpose(X,-5) ) +transpose(arpeggio(((transpose(X,4) +transpose((X+transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,7) ) +X) ,7) ) ) ,12) ) ,-5) +transpose(echo((X+transpose(X,7) ) ,4,6) ,4) ) +transpose(((((transpose((X+transpose(X,12) ) ,4) |transpose((X|X) ,-7) ) +transpose(transpose(transpose(arpeggio(X) ,4) ,4) ,7) ) +transpose(echo((echo(echo(X,4,6) ,4,6) |step(transpose((X|X) ,-7) ,12) ) ,4,6) ,7) ) +transpose(((arpeggio(arpeggio(X) ) +transpose(transpose(transpose(arpeggio(X) ,4) ,-5) ,12) ) +transpose(shuffle(transpose(transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X|X) ,12) ) ,-5) ,-5) ) ,12) ) ,7) ) ,7) ) ,4) ) +transpose(transpose(((transpose(transpose(transpose(transpose(X,4) ,-7) ,-7) ,-5) +transpose(transpose((((step(X,12) |X) +transpose(((X|X) +X) ,12) ) |echo(echo((X+transpose(X,7) ) ,4,6) ,4,6) ) ,4) ,12) ) +transpose(arpeggio(transpose(X,4) ) ,7) ) ,-7) ,7) ) ,7) ) ,-7) ) ) ,4) ) +transpose(transpose(shuffle((arpeggio(((((arpeggio(transpose((X+transpose(X,12) ) ,4) ) +transpose(transpose(X,-5) ,12) ) +transpose(step(((transpose(transpose(X,-7) ,-5) +transpose((step(X,12) |echo(X,4,6) ) ,4) ) +transpose(transpose(transpose(X,4) ,-7) ,7) ) ,12) ,12) ) +transpose(step(transpose(transpose(shuffle(arpeggio(X) ) ,-7) ,4) ,12) ,4) ) +transpose(transpose(transpose(step((transpose(X,-7) +transpose(X,7) ) ,12) ,-7) ,-5) ,7) ) ) +(transpose(transpose(transpose(step(((echo(X,4,6) +transpose(step(X,12) ,4) ) +transpose(X,7) ) ,12) ,4) ,4) ,-5) |transpose(transpose((shuffle(shuffle(transpose(X,-5) ) ) +transpose(shuffle(((transpose(X,-5) +transpose(step(X,12) ,4) ) +transpose((X|X) ,7) ) ) ,7) ) ,4) ,-5) ) ) ) ,4) ,7) ) ) ) random seed used was 164175387 EXPR = arpeggio(((transpose((((transpose(((((transpose(((transpose(X,4) +transpose(X,12) ) |(((step(X,12) +transpose(transpose(X,4) ,12) ) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) ) ,-7) |transpose((((transpose(X,-5) +transpose(X,12) ) +transpose(((X+transpose(X,12) ) |((X+transpose(shuffle(X) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,4) ) +transpose((arpeggio(transpose(X,-7) ) +transpose(X,7) ) ,7) ) ,4) ) +transpose((((transpose(X,-5) +transpose(transpose(shuffle(arpeggio(X) ) ,-7) ,4) ) +transpose(transpose(transpose((X|X) ,-7) ,4) ,7) ) |(step(((X+transpose(X,4) ) +transpose(shuffle(X) ,7) ) ,12) +transpose((transpose((X+transpose(X,7) ) ,4) +transpose(X,-5) ) ,7) ) ) ,12) ) +transpose(((((X|X) |X) |(transpose(X,-5) |(X+transpose(X,12) ) ) ) |(shuffle(X) +(((X+transpose(X,4) ) +transpose(X,7) ) |(X+transpose(X,12) ) ) ) ) ,4) ) +transpose(((arpeggio(X) +transpose(((transpose(transpose(shuffle(X) ,4) ,-7) +((X+transpose(X,7) ) +transpose(X,4) ) ) +transpose((X+transpose((X+transpose(X,12) ) ,12) ) ,12) ) ,7) ) |transpose((echo(shuffle(shuffle(X) ) ,4,6) +transpose(transpose((transpose(X,-7) |X) ,-7) ,7) ) ,-7) ) ,4) ) ,-5) +transpose(((transpose(transpose(transpose((transpose((X+transpose(arpeggio(X) ,12) ) ,-5) +transpose(step(echo((X+X) ,4,6) ,12) ,7) ) ,-5) ,4) ,-7) +transpose((transpose(transpose(transpose(((arpeggio(X) +transpose(echo(X,4,6) ,4) ) +transpose((X+X) ,7) ) ,4) ,4) ,4) +transpose((transpose(echo(((X|X) |X) ,4,6) ,4) +transpose(((((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) +transpose((step(X,12) +transpose(transpose(X,-7) ,12) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) |(transpose(X,4) +transpose((X+transpose(X,12) ) ,-7) ) ) +transpose(transpose(arpeggio((X|X) ) ,4) ,12) ) ,7) ) ,12) ) ,4) ) +transpose(((((transpose(X,4) +transpose(transpose(X,-5) ,7) ) +X) +transpose(transpose(X,-7) ,12) ) +transpose((transpose(X,4) |step(transpose(transpose(X,-5) ,-5) ,12) ) ,12) ) ,7) ) ,12) ) +transpose(((arpeggio(arpeggio(transpose((transpose(((X+X) |(X+transpose(X,12) ) ) ,4) |((shuffle(X) |transpose(X,4) ) |X) ) ,4) ) ) +transpose(transpose(step(echo(((echo(echo(X,4,6) ,4,6) |((transpose(X,-5) +transpose((X|X) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) +echo((transpose(X,-5) +transpose((transpose(X,4) +transpose(transpose(X,-7) ,7) ) ,12) ) ,4,6) ) ,4,6) ,12) ,-5) ,4) ) +transpose(transpose((((((transpose(X,-7) +transpose((X+X) ,12) ) +transpose((transpose(((transpose(transpose(X,4) ,4) +transpose((transpose(X,-7) +transpose((X|X) ,12) ) ,7) ) +transpose(((step((X|X) ,12) +transpose(((X+X) |X) ,12) ) +transpose(transpose(X,-7) ,12) ) ,12) ) ,4) |step(transpose(transpose(X,-5) ,-7) ,12) ) ,7) ) +transpose((((transpose(X,-5) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,12) ) +transpose(step((X+transpose(X,12) ) ,12) ,4) ) +transpose(step(shuffle(X) ,12) ,7) ) ,4) ) +transpose(transpose(((echo((X|X) ,4,6) +transpose(shuffle(transpose(X,-7) ) ,4) ) +transpose((((transpose(transpose(X,4) ,-5) +transpose((transpose(X,-5) |echo(X,4,6) ) ,4) ) +transpose((X+transpose((X|X) ,7) ) ,7) ) |step((step(X,12) +X) ,12) ) ,7) ) ,-5) ,7) ) +transpose(transpose(((arpeggio(transpose(transpose(X,-7) ,4) ) +transpose(transpose(arpeggio(X) ,4) ,7) ) +transpose(transpose(echo(shuffle(X) ,4,6) ,4) ,12) ) ,4) ,12) ) ,-7) ,7) ) ,12) ) +transpose(((((((transpose(transpose(transpose(shuffle(shuffle((X|(X+X) ) ) ) ,-7) ,-7) ,-5) +transpose((transpose((((echo(X,4,6) |(X|X) ) +transpose(transpose(transpose(X,-7) ,-7) ,7) ) +transpose(transpose(transpose(transpose(transpose(X,-5) ,4) ,-5) ,-7) ,7) ) ,-7) +transpose(shuffle(transpose(shuffle(X) ,-5) ) ,-7) ) ,4) ) +transpose((shuffle(echo(transpose(transpose(arpeggio(transpose(X,4) ) ,-5) ,4) ,4,6) ) +transpose(echo(echo(((X+((X+transpose(X,4) ) +transpose(X,7) ) ) |((X|X) |(X+X) ) ) ,4,6) ,4,6) ,12) ) ,7) ) |(transpose(transpose(arpeggio(transpose(arpeggio((X|X) ) ,-5) ) ,-5) ,-5) |arpeggio(arpeggio((transpose(transpose((X|X) ,-5) ,-7) +transpose(arpeggio(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) ,12) ) ) ) ) ) +transpose(((transpose(transpose(transpose(((X+transpose(shuffle(transpose(X,4) ) ,12) ) |((X|X) +transpose(transpose(X,-5) ,7) ) ) ,-5) ,-5) ,4) +((step(echo(X,4,6) ,12) |(((echo((X+transpose(X,7) ) ,4,6) +transpose((X|X) ,12) ) +transpose(echo((X+transpose(X,12) ) ,4,6) ,4) ) +transpose(X,7) ) ) |(transpose((transpose((X|X) ,4) |(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ) ,4) +transpose(shuffle(((X|X) +transpose(transpose(transpose(X,-5) ,-5) ,12) ) ) ,7) ) ) ) +transpose(shuffle(echo(transpose(step(transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-5) ,12) ,-7) ,4,6) ) ,12) ) ,4) ) +transpose(transpose(transpose(step(transpose(echo((((step(X,12) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose((((X|X) +transpose((X|X) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) |arpeggio(X) ) ,4,6) ,-5) ,12) ,-7) ,4) ,4) ) +transpose(step(((transpose((shuffle((X+transpose(X,12) ) ) +transpose(transpose(step(arpeggio(((X+transpose((X+transpose(X,12) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ) ,12) ,4) ,7) ) ,-7) +transpose(step(step(((transpose(X,4) +transpose((X|X) ,4) ) +transpose((X|X) ,7) ) ,12) ,12) ,12) ) +transpose(transpose(transpose(transpose((X+transpose(X,7) ) ,4) ,4) ,-5) ,7) ) ,12) ,7) ) ,12) ) ,-5) +transpose(shuffle(shuffle(transpose(arpeggio((transpose(((transpose(X,4) |shuffle(step(X,12) ) ) |(transpose(((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,7) ) ,4) +transpose(((((X+transpose(transpose(X,-5) ,4) ) +transpose(X,7) ) +transpose(X,7) ) +transpose(((arpeggio(X) |(X+transpose(X,12) ) ) +transpose(transpose((X+transpose(X,12) ) ,-7) ,7) ) ,12) ) ,7) ) ) ,-7) +transpose((transpose(((transpose((((transpose((X|X) ,-5) |X) +transpose(transpose(shuffle(X) ,4) ,4) ) +transpose((transpose(X,-5) +transpose(X,4) ) ,7) ) ,4) +transpose((((transpose(transpose(echo(X,4,6) ,-5) ,-7) +transpose((transpose(X,-5) +step(X,12) ) ,7) ) +transpose(echo(transpose(shuffle(X) ,-7) ,4,6) ,4) ) +transpose((transpose((X+transpose(transpose(X,-5) ,7) ) ,-5) |transpose(shuffle(X) ,-5) ) ,7) ) ,4) ) +transpose(echo(((X+transpose((transpose((X|X) ,-7) |transpose(X,-5) ) ,4) ) +transpose(step(transpose(X,4) ,12) ,7) ) ,4,6) ,7) ) ,-7) |step(((shuffle(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) +transpose(step(X,12) ,12) ) +transpose(transpose((echo(X,4,6) +transpose(step((X|X) ,12) ,7) ) ,4) ,7) ) ,12) ) ,12) ) ) ,-7) ) ) ,12) ) +transpose((transpose(transpose(shuffle(((shuffle(((step(transpose(transpose(transpose(X,4) ,-7) ,-7) ,12) +transpose((step((shuffle(X) |(transpose(shuffle(X) ,4) +transpose(X,4) ) ) ,12) |(echo((X|X) ,4,6) +transpose((transpose(X,-5) +shuffle(X) ) ,-5) ) ) ,4) ) +transpose((((echo(arpeggio(X) ,4,6) +transpose((arpeggio(step(X,12) ) |arpeggio(transpose(X,-5) ) ) ,4) ) +transpose((step(X,12) +transpose((X+transpose(X,12) ) ,12) ) ,7) ) +transpose(transpose(shuffle((((X+transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) +transpose(transpose((X+X) ,-5) ,7) ) ) ,-5) ,12) ) ,7) ) ) +transpose(((echo(transpose(step(echo(shuffle(X) ,4,6) ,12) ,4) ,4,6) +shuffle(transpose((echo(((X|X) +transpose(echo(X,4,6) ,7) ) ,4,6) |transpose(transpose((echo((X+X) ,4,6) +transpose(((X+transpose(X,7) ) +X) ,12) ) ,-5) ,-7) ) ,-7) ) ) |(transpose((transpose(transpose(echo(X,4,6) ,-7) ,-5) |(((((X|X) +transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ) +transpose((transpose(X,-5) |step(X,12) ) ,7) ) +transpose(step(transpose(X,4) ,12) ,4) ) +transpose(arpeggio(((X+transpose(X,7) ) +transpose(X,12) ) ) ,7) ) ) ,-5) +transpose(transpose(((X|arpeggio(X) ) |((X+transpose(X,7) ) +transpose(X,12) ) ) ,4) ,-7) ) ) ,4) ) +transpose((transpose(step(transpose(echo(arpeggio(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ,4,6) ,4) ,12) ,4) +transpose(transpose((transpose(transpose((transpose(((X+X) +X) ,4) |transpose((transpose(X,4) +transpose((X|X) ,12) ) ,4) ) ,-7) ,-5) +step(transpose((arpeggio(X) +transpose(transpose(transpose(X,-7) ,4) ,7) ) ,4) ,12) ) ,-5) ,7) ) ,7) ) ) ,-7) ,-5) +transpose(((arpeggio(((transpose(transpose(arpeggio((((echo(X,4,6) +transpose((X|X) ,4) ) +transpose(shuffle(X) ,7) ) +(X+transpose(X,7) ) ) ) ,-7) ,4) +transpose((echo(transpose((arpeggio(X) |step(X,12) ) ,-5) ,4,6) +transpose(arpeggio(((((transpose(((transpose(X,-7) +transpose(transpose(X,-5) ,4) ) +transpose(transpose(X,4) ,7) ) ,4) +transpose(X,4) ) +transpose(transpose(transpose((X+transpose(X,12) ) ,-7) ,-5) ,7) ) |(step(arpeggio((X+transpose(X,12) ) ) ,12) |transpose(step(transpose(X,-7) ,12) ,4) ) ) +transpose(shuffle(transpose(X,4) ) ,7) ) ) ,7) ) ,4) ) +transpose(arpeggio(shuffle(((transpose(transpose(((echo(X,4,6) +transpose(transpose(X,-7) ,4) ) +transpose(transpose(step(X,12) ,-7) ,7) ) ,4) ,4) +transpose(((X+transpose((X|X) ,7) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) |echo(X,4,6) ) ,7) ) ,4) ) +transpose((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +transpose(echo(shuffle(step(X,12) ) ,4,6) ,7) ) ,7) ) ) ) ,7) ) ) +transpose((transpose(echo((((transpose(transpose(X,4) ,-5) +transpose(step(transpose((X|X) ,-7) ,12) ,4) ) +transpose(((step(X,12) +transpose(transpose(arpeggio(X) ,-7) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,7) ) |transpose((((transpose(X,-5) |(X|(X+transpose(X,12) ) ) ) +transpose(((X+transpose(step(X,12) ,4) ) +transpose(transpose(X,-5) ,7) ) ,-7) ) |transpose((((X+transpose(X,7) ) +transpose(X,12) ) +transpose(arpeggio(echo(X,4,6) ) ,12) ) ,4) ) ,-7) ) ,4,6) ,-7) |shuffle(transpose(transpose((transpose(transpose(X,-7) ,-5) |transpose(X,-7) ) ,4) ,4) ) ) ,12) ) +transpose(((transpose((shuffle(echo(transpose((X+transpose(X,7) ) ,4) ,4,6) ) +transpose(transpose(arpeggio((transpose(X,4) |transpose(X,-7) ) ) ,-7) ,7) ) ,-5) |(((transpose(shuffle(shuffle(arpeggio(arpeggio(X) ) ) ) ,-5) |transpose(transpose((transpose(X,-7) |(arpeggio(X) |transpose((X+X) ,-7) ) ) ,-7) ,-7) ) +transpose(transpose(transpose((step(shuffle(X) ,12) |(arpeggio(X) |(X+transpose(X,7) ) ) ) ,4) ,-5) ,4) ) +transpose(transpose(transpose(step(transpose((X|(X+transpose(X,7) ) ) ,-7) ,12) ,4) ,-7) ,7) ) ) |echo(transpose((transpose(transpose(transpose(((X+transpose(X,7) ) +transpose((X+transpose(X,12) ) ,12) ) ,4) ,4) ,-5) |(((((step(arpeggio(X) ,12) |((X+transpose((X+transpose(X,12) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) +transpose(transpose((((X+X) +transpose(X,4) ) +transpose(shuffle(X) ,7) ) ,4) ,4) ) +transpose(transpose(step(X,12) ,-5) ,7) ) +transpose(transpose(transpose((X|X) ,-5) ,4) ,4) ) +transpose(transpose(((shuffle(transpose(X,-7) ) +transpose(step((X|X) ,12) ,4) ) +transpose((step(X,12) +transpose((X|X) ,12) ) ,7) ) ,-7) ,7) ) ) ,-5) ,4,6) ) ,7) ) ,12) ) ,-7) ) ) random seed used was 0

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