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(((shuffle(step(((((transpose(echo(transpose(step(shuffle((X+transpose(X,12) ) ) ,12) ,-5) ,4,6) ,-5) +transpose((echo(transpose(shuffle(transpose(transpose(X,4) ,4) ) ,-7) ,4,6) +echo((transpose(((echo(((step(X,12) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(transpose(X,-7) ,7) ) ,4,6) +transpose(transpose(((X+transpose(X,12) ) |arpeggio(X) ) ,4) ,4) ) +transpose(transpose(((X|X) +echo(X,4,6) ) ,-7) ,7) ) ,-7) |(((X+transpose(X,7) ) |transpose(transpose(X,-7) ,-7) ) +(((transpose(X,-7) |X) +transpose((X|X) ,7) ) |transpose(X,-7) ) ) ) ,4,6) ) ,4) ) +transpose(((transpose(transpose(((echo((X+transpose(X,12) ) ,4,6) +transpose(step(((X+transpose(X,4) ) +transpose(step(X,12) ,7) ) ,12) ,4) ) +transpose(((shuffle(X) +transpose(X,12) ) +step((X+transpose(X,12) ) ,12) ) ,7) ) ,-5) ,-7) +transpose(((echo((arpeggio(echo(X,4,6) ) +transpose(step((X|X) ,12) ,7) ) ,4,6) +transpose(arpeggio((transpose(transpose(X,4) ,4) +X) ) ,4) ) +transpose((((transpose((X+transpose(X,7) ) ,4) +transpose(((X+transpose(transpose(X,-7) ,7) ) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) +transpose(X,7) ) ,7) ) ,7) ) |arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ) +transpose(step(step(X,12) ,12) ,12) ) ,7) ) ,12) ) +transpose((((echo(((X|X) +transpose(echo(X,4,6) ,12) ) ,4,6) +transpose(step(echo(transpose(X,-7) ,4,6) ,12) ,-5) ) |shuffle(transpose((((X+transpose(shuffle(X) ,4) ) +transpose(X,7) ) +arpeggio(transpose(X,-7) ) ) ,-7) ) ) |echo(shuffle(echo((X+X) ,4,6) ) ,4,6) ) ,12) ) ,7) ) |echo(transpose((arpeggio(transpose(transpose(X,-5) ,-7) ) +arpeggio((((X+transpose(transpose(X,-7) ,7) ) +transpose(transpose(X,-7) ,12) ) +transpose(transpose((transpose(shuffle(X) ,-7) +transpose(X,7) ) ,-5) ,7) ) ) ) ,-7) ,4,6) ) +transpose(step((transpose(((arpeggio(transpose((((echo(transpose(X,-7) ,4,6) +transpose(echo(transpose(X,-7) ,4,6) ,4) ) +transpose(transpose(X,-7) ,7) ) +transpose((step(transpose((X|X) ,4) ,12) +arpeggio(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ) ) ,7) ) ,-7) ) +transpose((transpose(transpose(step(X,12) ,-7) ,-7) +transpose(((step(transpose(shuffle(X) ,-7) ,12) +transpose((((transpose(X,-7) +arpeggio(X) ) +transpose(arpeggio(step(X,12) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) +transpose(transpose((step(X,12) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ,-5) ,12) ) ,12) ) ,7) ) +((transpose(shuffle(X) ,-5) +transpose(transpose(transpose(X,4) ,-7) ,12) ) |((step(arpeggio((X|step(X,12) ) ) ,12) +transpose((arpeggio(transpose(transpose((X+transpose(X,12) ) ,-5) ,-7) ) +transpose(echo((((transpose(X,-7) +arpeggio(X) ) +transpose((X+X) ,7) ) +transpose((((X|(X+transpose(X,12) ) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,-7) ,7) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ,12) ) ,4,6) ,12) ) ,4) ) +transpose((transpose((echo((X+transpose(X,7) ) ,4,6) |transpose((step(X,12) +transpose(X,7) ) ,-7) ) ,-7) +transpose(echo(((((X|X) +transpose(X,7) ) +transpose((X+X) ,4) ) +transpose(step(X,12) ,7) ) ,4,6) ,-7) ) ,7) ) ) ) ,-7) +transpose(transpose((((transpose(transpose(step(step(((step(X,12) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,4) ) +transpose(X,7) ) ,12) ,12) ,-5) ,-7) +transpose(transpose(step((shuffle(((X+transpose(shuffle(X) ,12) ) +transpose(shuffle(transpose(X,-7) ) ,12) ) ) +transpose(transpose(X,4) ,7) ) ,12) ,-7) ,7) ) +transpose(((transpose(shuffle(arpeggio(transpose((X+transpose(transpose(X,4) ,12) ) ,-7) ) ) ,-7) +transpose((((((X|X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose((echo(transpose(X,-7) ,4,6) +transpose(step(X,12) ,12) ) ,7) ) +transpose((((transpose(((X+transpose(X,12) ) +X) ,-7) +transpose((transpose(arpeggio(X) ,-7) +transpose(transpose((transpose(X,4) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,-7) ,12) ) ,4) ) +transpose(arpeggio(step((X+transpose(X,12) ) ,12) ) ,7) ) |(shuffle(transpose(transpose(transpose(X,-5) ,-7) ,4) ) +(transpose(transpose(X,4) ,-5) +transpose(X,12) ) ) ) ,4) ) +transpose(arpeggio(transpose(arpeggio(X) ,-7) ) ,7) ) ,4) ) +transpose(step((transpose((X|X) ,-5) |arpeggio(X) ) ,12) ,7) ) ,4) ) +transpose(((arpeggio(((step(X,12) |arpeggio(X) ) +step(X,12) ) ) +transpose((transpose(transpose(transpose(X,-7) ,-5) ,-7) +transpose(((X+(X+transpose(transpose(X,-7) ,7) ) ) +transpose((shuffle(X) |shuffle(echo(shuffle(X) ,4,6) ) ) ,7) ) ,7) ) ,4) ) +transpose(transpose((transpose(X,-7) +transpose(arpeggio(X) ,12) ) ,-5) ,7) ) ,7) ) ,-5) ,7) ) ,12) ,12) ) ,12) ) +transpose(echo((arpeggio(shuffle((transpose(transpose(arpeggio((((transpose(echo(arpeggio(X) ,4,6) ,-7) +transpose(step(echo(X,4,6) ,12) ,4) ) +transpose(step(step(step(X,12) ,12) ,12) ,7) ) +transpose((((shuffle(step(X,12) ) +step(transpose((X+transpose(X,7) ) ,4) ,12) ) +transpose(((X+transpose(echo(X,4,6) ,4) ) +transpose(step(X,12) ,7) ) ,4) ) +transpose(step(step((X+X) ,12) ,12) ,7) ) ,12) ) ) ,-7) ,-7) |transpose(((echo(transpose(X,-5) ,4,6) +transpose(transpose(arpeggio(X) ,-7) ,7) ) +transpose(arpeggio((transpose(transpose(X,-7) ,-7) +transpose(((transpose(X,4) +transpose(shuffle(X) ,4) ) +transpose(arpeggio(X) ,7) ) ,12) ) ) ,7) ) ,-5) ) ) ) +transpose(transpose(((transpose(echo(transpose((((((X+transpose((X+transpose(X,12) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) +transpose((X|X) ,12) ) |((X+transpose(X,7) ) +((arpeggio(X) +transpose(transpose(X,-7) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ) ) +transpose(arpeggio((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,12) ) ) ,7) ) ,4) ,4,6) ,4) +transpose(((((echo(arpeggio((X+transpose(X,7) ) ) ,4,6) +transpose(transpose(X,4) ,7) ) +arpeggio(shuffle(((arpeggio(X) +transpose((X+X) ,4) ) +transpose(shuffle(X) ,7) ) ) ) ) |(X+transpose((X+transpose(X,12) ) ,4) ) ) +transpose(arpeggio(transpose((transpose(arpeggio(X) ,4) +(X+transpose(X,7) ) ) ,-7) ) ,12) ) ,4) ) +transpose((((echo(((transpose((X+transpose((X+transpose(X,7) ) ,7) ) ,-7) +transpose((X+transpose(X,-7) ) ,12) ) +((X|arpeggio(X) ) +transpose(X,7) ) ) ,4,6) +transpose((step(arpeggio((transpose(X,-7) +transpose((X+transpose(X,12) ) ,12) ) ) ,12) +(((X+transpose(X,12) ) |(((X+transpose(X,7) ) +transpose(arpeggio(X) ,4) ) +transpose(X,7) ) ) +transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ) ) ,12) ) +transpose(((transpose(arpeggio(X) ,4) +transpose(transpose((shuffle(X) +transpose((X+echo(X,4,6) ) ,12) ) ,-7) ,7) ) +transpose(X,12) ) ,4) ) +transpose(step(((echo((X+X) ,4,6) +transpose((arpeggio(X) |((X|X) +transpose(X,7) ) ) ,12) ) +transpose(transpose(echo((X+transpose(X,7) ) ,4,6) ,4) ,7) ) ,12) ,7) ) ,7) ) ,-5) ,7) ) ,4,6) ,12) ) +transpose(arpeggio((step(((shuffle(transpose(transpose(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ,-7) ,4) ) +(transpose((step(X,12) +arpeggio(X) ) ,-7) +transpose(echo(((X+X) |(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(echo(X,4,6) ,12) ) ) ,4,6) ,12) ) ) +transpose(step(echo(transpose((((transpose(X,-5) +X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(((echo(X,4,6) |shuffle(X) ) +transpose((transpose(X,-5) |X) ,12) ) ,7) ) ,4) ,4,6) ,12) ,12) ) ,12) +transpose(transpose((transpose(((transpose(((step((transpose(X,-7) +X) ,12) +transpose((transpose(transpose(echo((X+transpose(X,7) ) ,4,6) ,-7) ,-7) +transpose(transpose((transpose(transpose(X,4) ,-7) +transpose(transpose(shuffle(X) ,-7) ,12) ) ,-7) ,12) ) ,4) ) +transpose((((((((X+X) +transpose(step(X,12) ,4) ) +transpose((transpose(X,-7) +X) ,7) ) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(transpose(echo(X,4,6) ,-7) ,-7) ,7) ) +transpose(shuffle((X+transpose(step(X,12) ,12) ) ) ,4) ) +transpose(transpose(((X|X) +transpose(arpeggio(X) ,12) ) ,4) ,7) ) ,7) ) ,-7) +transpose(transpose(transpose(echo(transpose(transpose(X,-7) ,4) ,4,6) ,-7) ,4) ,4) ) +transpose(arpeggio((step(echo(arpeggio(X) ,4,6) ,12) +(shuffle(shuffle(echo(X,4,6) ) ) +transpose((step((X+transpose((X+X) ,7) ) ,12) +transpose(step(transpose(shuffle(X) ,-7) ,12) ,12) ) ,12) ) ) ) ,7) ) ,-7) +transpose(transpose(echo((((shuffle(X) +transpose(X,7) ) +transpose(echo(arpeggio(X) ,4,6) ,12) ) +transpose((transpose(X,-7) |X) ,-7) ) ,4,6) ,-7) ,-5) ) ,-7) ,7) ) ) ,12) ) ) |transpose((echo(transpose((step((((echo((X+X) ,4,6) |transpose(step(arpeggio((X+transpose(X,7) ) ) ,12) ,-7) ) +transpose(transpose(((arpeggio(shuffle(X) ) +transpose(((transpose(X,-5) +transpose((X+transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,12) ) |((X+transpose(X,7) ) |transpose(X,-5) ) ) ,-7) ,4) ) +transpose(step(((transpose((((arpeggio(X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,4) ,7) ) +transpose(X,7) ) ,-7) +transpose(arpeggio(shuffle(step(echo(X,4,6) ,12) ) ) ,12) ) +transpose(shuffle(shuffle(shuffle(echo(echo((X+transpose(X,12) ) ,4,6) ,4,6) ) ) ) ,12) ) ,12) ,7) ) ,12) +transpose(arpeggio(((transpose(transpose(arpeggio(transpose(echo(transpose(X,-5) ,4,6) ,-7) ) ,-7) ,-7) +(step(transpose((shuffle(transpose(X,-7) ) +echo(X,4,6) ) ,-7) ,12) +transpose(((step(transpose(X,4) ,12) +transpose(((X+X) +transpose(X,7) ) ,4) ) +transpose(((transpose(X,4) +transpose(X,12) ) +transpose(X,7) ) ,7) ) ,12) ) ) +transpose(echo(transpose(step(X,12) ,-7) ,4,6) ,7) ) ) ,7) ) ,-5) ,4,6) +transpose((shuffle(((echo((echo(((shuffle((((X+transpose(X,4) ) +transpose(X,7) ) |arpeggio((X+X) ) ) ) +transpose(((X+transpose((X+transpose(X,12) ) ,7) ) +transpose(transpose(step(X,12) ,-7) ,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) ,4,6) +transpose(arpeggio((((X+transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose((transpose(X,4) +transpose((X+transpose(X,7) ) ,12) ) ,7) ) +transpose(echo(X,4,6) ,12) ) ) ,7) ) ,4,6) +transpose(((((transpose(echo(transpose(step((X|X) ,12) ,-7) ,4,6) ,4) +transpose(echo((((X|X) +transpose(shuffle(X) ,4) ) +transpose(shuffle(X) ,7) ) ,4,6) ,4) ) +transpose(transpose(((((echo(shuffle(step(X,12) ) ,4,6) +transpose(arpeggio(arpeggio(((echo(X,4,6) +transpose(transpose(X,-7) ,4) ) +transpose(shuffle(X) ,7) ) ) ) ,7) ) +transpose(echo(transpose((transpose(X,-7) +transpose(shuffle(X) ,12) ) ,-7) ,4,6) ,4) ) +transpose(echo((transpose(transpose(X,-7) ,-7) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,12) ) ,4,6) ,7) ) +transpose((shuffle((((((X+transpose(X,12) ) +transpose(X,4) ) +transpose((X|X) ,7) ) +((X+transpose(X,7) ) +X) ) |((X+transpose(X,7) ) +transpose(arpeggio(X) ,7) ) ) ) +transpose((((transpose(X,-7) +transpose((X+transpose(X,12) ) ,7) ) +((transpose(X,4) +transpose(X,7) ) +transpose(X,7) ) ) |((transpose(X,4) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,12) ) ,7) ) ,-7) ,7) ) +transpose(((step((X+X) ,12) +transpose((echo((((transpose(shuffle(X) ,-5) +transpose(arpeggio(shuffle(X) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) +transpose(step(step(X,12) ,12) ,7) ) ,7) ) ,4,6) +transpose(step((((echo(X,4,6) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) +transpose(((shuffle(X) +transpose(echo(X,4,6) ,12) ) +transpose(step(transpose(X,-5) ,12) ,7) ) ,7) ) +transpose(transpose(echo(X,4,6) ,-7) ,7) ) ,12) ,12) ) ,12) ) +transpose(((echo(((((transpose(X,4) |transpose(X,-5) ) +transpose(((X+transpose((X+transpose(X,12) ) ,7) ) |X) ,4) ) +transpose((echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) +(X+transpose((X|X) ,7) ) ) ,7) ) +arpeggio(X) ) ,4,6) +transpose((transpose(transpose((X+transpose(X,12) ) ,-7) ,-7) |(X+transpose(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ,12) ) ) ,7) ) +transpose(transpose(((((X+transpose(transpose(X,-7) ,4) ) +transpose(X,7) ) +transpose(transpose(((echo((X+transpose(X,7) ) ,4,6) +transpose(X,7) ) +transpose(transpose(shuffle(X) ,-7) ,7) ) ,-7) ,12) ) +transpose(((transpose(transpose(transpose(X,-5) ,-7) ,-7) +transpose(arpeggio((step(X,12) +transpose(X,7) ) ) ,4) ) +transpose((transpose(echo((X+transpose(X,7) ) ,4,6) ,-7) +transpose(transpose(transpose(arpeggio(X) ,-7) ,-5) ,7) ) ,7) ) ,7) ) ,-7) ,12) ) ,12) ) ,4) ) +transpose((echo((step(transpose((step(transpose((X|X) ,-5) ,12) +transpose(step((arpeggio(X) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ,7) ) ,-7) ,12) +transpose(echo(echo(transpose(echo(transpose(transpose(X,-5) ,-5) ,4,6) ,4) ,4,6) ,4,6) ,12) ) ,4,6) +transpose(transpose(transpose(((transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(echo((X+transpose(X,12) ) ,4,6) ,7) ) ,-5) +transpose(step(shuffle(transpose(transpose((X+transpose(X,12) ) ,-5) ,4) ) ,12) ,12) ) |arpeggio(arpeggio(transpose(shuffle(echo(X,4,6) ) ,-7) ) ) ) ,-7) ,4) ,12) ) ,7) ) ,4) ) +transpose(transpose(arpeggio(shuffle(((echo(echo(X,4,6) ,4,6) +X) +transpose(step(X,12) ,7) ) ) ) ,-5) ,7) ) ) +transpose((step((((((echo(transpose(transpose(X,-5) ,4) ,4,6) +transpose(transpose(echo(X,4,6) ,-5) ,4) ) +transpose(shuffle(step(((transpose(((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(arpeggio((X+transpose(X,12) ) ) ,12) ) +transpose(arpeggio(X) ,4) ) +transpose(((X+transpose(X,12) ) |echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ) ,7) ) |(((X+transpose(X,4) ) +transpose(X,7) ) |X) ) ,4) +transpose((transpose(((X+transpose(X,12) ) +transpose(arpeggio(X) ,12) ) ,-7) +transpose(transpose((X+transpose((X+transpose(X,7) ) ,7) ) ,-5) ,12) ) ,4) ) +transpose(((arpeggio((X+transpose(X,12) ) ) +transpose(transpose(echo(step(X,12) ,4,6) ,-5) ,4) ) +transpose(echo((echo(((step(X,12) +transpose(X,4) ) +transpose(transpose(X,-5) ,7) ) ,4,6) +transpose((X+X) ,12) ) ,4,6) ,7) ) ,7) ) ,12) ) ,7) ) +transpose(transpose(step(transpose(transpose(transpose(shuffle(((arpeggio(X) +transpose((X+transpose(X,12) ) ,4) ) +transpose(X,7) ) ) ,-5) ,4) ,-5) ,12) ,-5) ,12) ) +transpose((arpeggio(transpose((transpose((echo(transpose(shuffle(echo(X,4,6) ) ,4) ,4,6) +transpose((((X+transpose(X,12) ) +transpose(X,12) ) +transpose((X+transpose(transpose(X,-5) ,7) ) ,-7) ) ,12) ) ,-5) +transpose(step((X+transpose(echo((X+transpose(X,12) ) ,4,6) ,12) ) ,12) ,-7) ) ,-5) ) +transpose((arpeggio((shuffle((((step(step(X,12) ,12) +transpose(shuffle((shuffle(X) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,4) ) +transpose(step(shuffle((X+transpose(X,12) ) ) ,12) ,7) ) +step(((((X+X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(X,7) ) |step((X+transpose(X,12) ) ,12) ) ,12) ) ) +transpose(arpeggio((((X+transpose(X,7) ) +((X+transpose(X,12) ) +transpose(X,7) ) ) +transpose(transpose(((X+transpose(X,7) ) +transpose(transpose(arpeggio(X) ,-5) ,12) ) ,4) ,12) ) ) ,7) ) ) +transpose(((((((X+X) +transpose(transpose((X+transpose(X,7) ) ,-7) ,12) ) +transpose(transpose(step(X,12) ,-7) ,7) ) +transpose(step(((shuffle(X) +transpose(X,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ,4) ) +transpose((arpeggio(transpose(X,-7) ) +transpose(echo(transpose(X,-7) ,4,6) ,7) ) ,7) ) +transpose(arpeggio(arpeggio(step(shuffle(transpose(((X+transpose(X,12) ) +transpose(X,12) ) ,4) ) ,12) ) ) ,7) ) ,7) ) ,7) ) ,4) ) +transpose(shuffle(step(((step(((transpose(transpose(X,-5) ,-5) +transpose(X,4) ) +transpose(step(X,12) ,7) ) ,12) +transpose(transpose(X,4) ,12) ) +transpose(((arpeggio(transpose(arpeggio(shuffle(echo(X,4,6) ) ) ,-7) ) +transpose((step(transpose(X,-5) ,12) +transpose((step(echo(X,4,6) ,12) +transpose(transpose(X,-7) ,7) ) ,7) ) ,4) ) +transpose(shuffle((echo(arpeggio(arpeggio(X) ) ,4,6) +transpose((X+transpose(transpose(X,-5) ,12) ) ,-5) ) ) ,7) ) ,12) ) ,12) ) ,7) ) ,12) +(transpose((transpose(shuffle(arpeggio(transpose(shuffle(transpose((((X|X) +transpose(transpose(shuffle(X) ,-7) ,12) ) |transpose((X+transpose(X,12) ) ,-5) ) ,-5) ) ,4) ) ) ,-7) |transpose(((shuffle(transpose(transpose(shuffle(transpose((((arpeggio(transpose(X,4) ) +transpose((shuffle((X+X) ) +arpeggio(X) ) ,12) ) +transpose(transpose(((echo(X,4,6) +transpose((X+transpose(X,7) ) ,12) ) +transpose(arpeggio(X) ,12) ) ,-7) ,4) ) +transpose(echo(shuffle(X) ,4,6) ,7) ) ,-5) ) ,-5) ,-7) ) +transpose(arpeggio(transpose(echo(step(echo((X|X) ,4,6) ,12) ,4,6) ,4) ) ,4) ) +transpose(transpose((arpeggio(transpose(step((transpose(arpeggio(X) ,-7) +transpose(((transpose(arpeggio(X) ,-5) +transpose(echo((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,-7) ,12) ) ,4,6) ,4) ) +transpose((shuffle(X) +transpose(X,7) ) ,7) ) ,12) ) ,12) ,-7) ) |((arpeggio(arpeggio(echo((transpose(X,-7) +transpose(X,7) ) ,4,6) ) ) +transpose(transpose(((shuffle(X) +transpose(transpose(arpeggio(X) ,4) ,7) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ,7) ) +transpose(transpose(transpose(((((shuffle((X+transpose(X,12) ) ) +transpose(shuffle(X) ,4) ) +transpose(X,7) ) +transpose(echo(transpose(arpeggio(X) ,-7) ,4,6) ,7) ) |(step((X+transpose(echo(X,4,6) ,7) ) ,12) +transpose((X|X) ,4) ) ) ,4) ,4) ,12) ) ) ,4) ,7) ) ,4) ) ,4) +transpose(((transpose(transpose(((shuffle(echo(echo(X,4,6) ,4,6) ) +transpose(transpose(transpose(X,-7) ,-5) ,7) ) +transpose(transpose(((X+transpose((X+transpose(X,7) ) ,7) ) +transpose(transpose(X,-5) ,12) ) ,-7) ,7) ) ,-5) ,-7) |echo(((((arpeggio(transpose(arpeggio(X) ,-5) ) +transpose((transpose(X,-7) +transpose(transpose(X,-5) ,12) ) ,4) ) +transpose((step((X+transpose(X,12) ) ,12) +((X+transpose((X+X) ,4) ) +transpose(X,7) ) ) ,7) ) +(transpose(transpose(echo(X,4,6) ,4) ,-7) +transpose(arpeggio(transpose(transpose(X,-7) ,-7) ) ,12) ) ) +transpose(echo((((transpose(((transpose(X,4) +transpose(echo(X,4,6) ,4) ) +transpose(X,7) ) ,-5) +transpose(arpeggio((transpose(shuffle(X) ,-7) +transpose(((X+transpose(step(X,12) ,4) ) +transpose(echo(X,4,6) ,7) ) ,7) ) ) ,4) ) +transpose(transpose(transpose(transpose(X,-7) ,4) ,-7) ,7) ) +transpose(((shuffle((arpeggio(X) |(X+X) ) ) +transpose(((X+X) +transpose(X,12) ) ,4) ) +transpose(shuffle(((X+transpose(transpose(X,-5) ,7) ) +transpose(transpose(X,-5) ,7) ) ) ,7) ) ,12) ) ,4,6) ,7) ) ,4,6) ) +shuffle(echo(transpose(transpose((arpeggio(transpose(arpeggio(transpose(((X+transpose(X,12) ) +transpose(echo(X,4,6) ,12) ) ,-5) ) ,-7) ) +transpose(arpeggio((echo(((((X|X) +transpose(X,12) ) +transpose((transpose(X,4) +transpose(X,12) ) ,7) ) +arpeggio((echo(X,4,6) +transpose(transpose(X,4) ,12) ) ) ) ,4,6) +arpeggio(arpeggio(X) ) ) ) ,-5) ) ,-7) ,-5) ,4,6) ) ) ,12) ) ) ,12) ) ,7) ) ,-5) ) random seed used was 3691115

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