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:
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After 20 generations the expression "X" became this:
arpeggio(transpose(arpeggio(transpose(transpose(step(((echo(step((shuffle((((X+transpose(X,7) ) +transpose(echo(((X+X) |(X|X) ) ,4,6) ,4) ) +transpose(((X+transpose(transpose(X,4) ,4) ) +transpose(shuffle(X) ,7) ) ,7) ) ) +transpose(echo(((arpeggio(step(echo(X,4,6) ,12) ) +transpose(shuffle(transpose(X,-7) ) ,4) ) +transpose(arpeggio(X) ,7) ) ,4,6) ,7) ) ,12) ,4,6) +transpose(((echo(arpeggio((X|X) ) ,4,6) +transpose(echo(echo(((X|X) +X) ,4,6) ,4,6) ,4) ) +transpose(((((arpeggio(X) +transpose(echo((X+transpose(X,7) ) ,4,6) ,4) ) +transpose(arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ,7) ) +transpose(transpose(((step(X,12) +transpose(arpeggio(X) ,4) ) +transpose(arpeggio(X) ,7) ) ,-5) ,4) ) +transpose(step(arpeggio(shuffle(X) ) ,12) ,7) ) ,7) ) ,7) ) +echo((((transpose(transpose(((arpeggio(X) +transpose((X+transpose(X,12) ) ,4) ) +transpose(X,7) ) ,4) ,-7) |((transpose((X|X) ,-7) |echo(step(X,12) ,4,6) ) +transpose(echo(((X|X) |((X+transpose(X,4) ) +transpose(X,7) ) ) ,4,6) ,7) ) ) +transpose((step((((shuffle((step(X,12) +transpose(shuffle(X) ,12) ) ) +transpose(transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,4) ) +transpose(X,7) ) ,-7) ,12) ) +transpose((shuffle(shuffle((X|X) ) ) +transpose(echo(X,4,6) ,4) ) ,4) ) +transpose((step((X+X) ,12) |step(X,12) ) ,7) ) ,12) |step(((step(X,12) +transpose((X+X) ,12) ) |shuffle((X+transpose(X,12) ) ) ) ,12) ) ,4) ) +transpose(shuffle(echo(shuffle((echo(arpeggio(step(X,12) ) ,4,6) +transpose(transpose(transpose(arpeggio(echo(X,4,6) ) ,4) ,4) ,12) ) ) ,4,6) ) ,7) ) ,4,6) ) ,12) ,-5) ,-5) ) ,-7) )
random seed used was 216648728 EXPR = transpose((transpose((echo((echo((((X+X) +transpose((((X+X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,7) ) +transpose(transpose(shuffle(X) ,-5) ,12) ) ,4,6) +(((step(((X+transpose(X,12) ) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) |transpose((((((X+transpose(transpose(X,4) ,4) ) +transpose(X,7) ) +(step(X,12) +transpose(X,7) ) ) +transpose(((step(step((X|X) ,12) ,12) +transpose(step((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(echo(X,4,6) ,7) ) ,12) ,4) ) +transpose(step(shuffle((X+transpose(X,12) ) ) ,12) ,7) ) ,4) ) +transpose(((((echo(X,4,6) +transpose(transpose(transpose(X,-7) ,-7) ,4) ) +transpose((arpeggio(X) +transpose(X,7) ) ,7) ) +transpose(shuffle(transpose(X,4) ) ,4) ) +transpose(X,7) ) ,7) ) ,4) ) +transpose((arpeggio(step(transpose((transpose(X,-5) +X) ,-7) ,12) ) |arpeggio((X+(X+transpose(X,12) ) ) ) ) ,4) ) +transpose(((shuffle(shuffle(transpose(shuffle((shuffle(X) +transpose(echo((X|X) ,4,6) ,12) ) ) ,4) ) ) +transpose(arpeggio(echo(step(shuffle(arpeggio(X) ) ,12) ,4,6) ) ,4) ) +transpose(arpeggio(arpeggio(echo(transpose(transpose(echo(X,4,6) ,-7) ,-5) ,4,6) ) ) ,7) ) ,7) ) ) ,4,6) |transpose(((((((shuffle(echo(echo(echo(X,4,6) ,4,6) ,4,6) ) +transpose((arpeggio((X+transpose(arpeggio(shuffle(X) ) ,7) ) ) +(arpeggio(((X+transpose(X,4) ) +transpose(shuffle(X) ,7) ) ) +transpose(arpeggio(step(step((X|X) ,12) ,12) ) ,12) ) ) ,12) ) +transpose(echo((((X|X) +transpose(echo(X,4,6) ,7) ) |arpeggio(transpose(X,4) ) ) ,4,6) ,4) ) +transpose((echo(transpose((X+transpose(X,12) ) ,-5) ,4,6) |((step(echo((transpose(X,4) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,4,6) ,12) +transpose(((echo(step(X,12) ,4,6) +transpose(transpose(echo(X,4,6) ,4) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4) ) +transpose(shuffle((step(X,12) +arpeggio((X+X) ) ) ) ,7) ) ) ,7) ) +transpose(transpose(echo(((echo((step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) +X) ,4,6) +transpose(((transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) +transpose((transpose((transpose(X,-7) +transpose(arpeggio(X) ,12) ) ,-5) +transpose(shuffle(((X+transpose(X,4) ) +transpose(X,7) ) ) ,12) ) ,4) ) +transpose(((((X+transpose(X,4) ) +transpose(X,7) ) +X) +transpose((((X+transpose(X,12) ) +shuffle(X) ) +transpose(transpose(X,-5) ,-7) ) ,7) ) ,7) ) ,4) ) +transpose(transpose((transpose(X,-7) |arpeggio(step(X,12) ) ) ,-7) ,7) ) ,4,6) ,-5) ,4) ) +transpose((((((echo((((((X+transpose(shuffle(X) ,4) ) +transpose(shuffle(X) ,7) ) +(echo(X,4,6) +transpose((X|X) ,7) ) ) +transpose((arpeggio(X) +((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ,12) ) ,7) ) ,4,6) |echo(echo(arpeggio((X|X) ) ,4,6) ,4,6) ) +transpose(shuffle(echo(step(arpeggio((X+transpose(X,7) ) ) ,12) ,4,6) ) ,4) ) +transpose(transpose(shuffle(echo(transpose(step(X,12) ,-7) ,4,6) ) ,-7) ,7) ) +step(((transpose(arpeggio(X) ,4) +transpose(arpeggio(step(X,12) ) ,4) ) +transpose(transpose(X,4) ,7) ) ,12) ) +transpose(transpose(step(step(((transpose(X,-7) +transpose(transpose(((X+transpose(X,7) ) +arpeggio(((X+transpose(X,4) ) +transpose(X,7) ) ) ) ,-7) ,4) ) +transpose(transpose((((transpose(X,4) +arpeggio(X) ) +transpose(transpose(X,-7) ,4) ) +transpose(arpeggio(transpose(X,4) ) ,7) ) ,4) ,7) ) ,12) ,12) ,4) ,12) ) ,7) ) |echo(step(arpeggio(arpeggio(((transpose(transpose(transpose(X,-5) ,4) ,-5) +transpose(transpose(transpose(((transpose(X,-5) +transpose((X+transpose(X,7) ) ,4) ) +transpose(transpose(X,-5) ,7) ) ,4) ,4) ,4) ) +transpose(step(X,12) ,7) ) ) ) ,12) ,4,6) ) ,-5) ) ,-7) +transpose(transpose(transpose((echo(arpeggio(step((X+X) ,12) ) ,4,6) +transpose(transpose((((step(echo(((transpose(step(X,12) ,4) +transpose(transpose((X+transpose(X,7) ) ,4) ,4) ) +transpose((shuffle(X) +X) ,7) ) ,4,6) ,12) |transpose(((transpose(X,-7) +transpose((step(X,12) +X) ,4) ) +transpose((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,4) ,12) ) ,7) ) ,4) ) +step(((((((shuffle(X) +transpose(shuffle(X) ,4) ) +transpose(echo(X,4,6) ,7) ) +((X+transpose(step(X,12) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ) |(transpose(X,-7) +transpose(step(X,12) ,12) ) ) +transpose(step((echo(X,4,6) +arpeggio(shuffle(X) ) ) ,12) ,7) ) +shuffle(shuffle(step(arpeggio(X) ,12) ) ) ) ,12) ) +step(shuffle((((arpeggio(((((X+transpose(X,4) ) +transpose(X,7) ) +X) +transpose((X+transpose((X|X) ,12) ) ,7) ) ) +transpose((echo((transpose(X,-5) +X) ,4,6) |(((X+transpose(X,12) ) +transpose(X,4) ) +transpose(transpose(echo(X,4,6) ,4) ,7) ) ) ,4) ) +transpose((arpeggio(echo(step(X,12) ,4,6) ) +transpose(transpose(X,4) ,-5) ) ,7) ) +echo(transpose(arpeggio(X) ,-5) ,4,6) ) ) ,12) ) ,-5) ,12) ) ,4) ,-5) ,7) ) ,4)
random seed used was 0 EXPR = arpeggio((echo(echo(((((X+transpose(X,4) ) +transpose(X,7) ) |(((step(echo(X,4,6) ,12) +transpose(transpose(X,-7) ,4) ) +transpose((X+arpeggio(X) ) ,7) ) +step(((X|transpose(X,-7) ) +transpose(transpose(X,-5) ,12) ) ,12) ) ) +transpose(transpose(transpose((arpeggio(shuffle(arpeggio((X+transpose(transpose((X|X) ,-5) ,7) ) ) ) ) +((step(X,12) |step((X+transpose(X,7) ) ,12) ) +transpose(X,4) ) ) ,4) ,-5) ,12) ) ,4,6) ,4,6) +((transpose(((transpose((shuffle(transpose(transpose((X+X) ,-7) ,4) ) +(arpeggio(((transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,-7) +transpose(transpose((X|((X+transpose(X,4) ) +transpose(X,7) ) ) ,-5) ,4) ) +transpose((X+arpeggio(transpose(X,4) ) ) ,7) ) ) +transpose(step((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X+X) ,4) ) +transpose(X,7) ) |(X|X) ) ,12) ,12) ) ) ,-5) +transpose(shuffle(step(echo(echo(((X+transpose(X,7) ) +transpose(X,7) ) ,4,6) ,4,6) ,12) ) ,4) ) +transpose(shuffle((transpose(((((shuffle(X) +X) +transpose(transpose((echo(echo(X,4,6) ,4,6) |shuffle(X) ) ,-5) ,4) ) +transpose(((((X|X) |X) |transpose((X+transpose(X,7) ) ,4) ) |step(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,12) ) ,7) ) +transpose(((transpose((X+transpose(X,12) ) ,-7) +transpose(arpeggio(((shuffle(X) +transpose(step(X,12) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) ,4) ) +transpose(((arpeggio(transpose(X,-5) ) +transpose(shuffle(X) ,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ,7) ) ,-5) +arpeggio(arpeggio(((transpose(X,-7) +step(X,12) ) |transpose(X,-5) ) ) ) ) ) ,7) ) ,-5) +transpose(transpose(((transpose(transpose(shuffle(transpose(X,-7) ) ,4) ,-5) +transpose(arpeggio(step((transpose((X+transpose(step(X,12) ,7) ) ,4) +transpose(((((((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(X,7) ) +transpose(((transpose(X,-7) +transpose(arpeggio(X) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) +transpose(step(shuffle(X) ,12) ,4) ) +transpose(shuffle(arpeggio(X) ) ,7) ) +transpose(echo(X,4,6) ,7) ) +transpose(echo(echo(transpose(echo(step(X,12) ,4,6) ,4) ,4,6) ,4,6) ,4) ) +transpose((echo(arpeggio(X) ,4,6) |((X|echo(((transpose(X,4) +transpose((X+transpose(X,7) ) ,4) ) +transpose((X+transpose(X,7) ) ,7) ) ,4,6) ) +transpose(((X+transpose(X,7) ) +transpose((transpose(X,-5) |X) ,12) ) ,12) ) ) ,7) ) ,12) ) ,12) ) ,4) ) +transpose(((transpose((((echo(X,4,6) +transpose(step((transpose(X,-5) +X) ,12) ,4) ) +transpose(echo((X+transpose(X,12) ) ,4,6) ,7) ) |transpose((X+transpose(arpeggio((((X+X) +transpose(X,4) ) +transpose(X,7) ) ) ,12) ) ,-5) ) ,-7) +transpose(transpose(((transpose(echo((((X+transpose((X+X) ,4) ) +transpose((X|X) ,7) ) +step(transpose(X,-7) ,12) ) ,4,6) ,-5) +transpose((((arpeggio(arpeggio((arpeggio(step(X,12) ) |X) ) ) +transpose(shuffle(step(shuffle(((transpose(arpeggio(X) ,4) +transpose(step(arpeggio(X) ,12) ,4) ) +transpose(shuffle(shuffle(X) ) ,7) ) ) ,12) ) ,7) ) +transpose((echo(echo(shuffle(transpose(echo(transpose(X,-7) ,4,6) ,-5) ) ,4,6) ,4,6) |transpose(echo(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-7) ,4,6) ,4) ) ,4) ) +transpose(transpose(echo(transpose((X|X) ,4) ,4,6) ,-7) ,7) ) ,4) ) +transpose(arpeggio((transpose(((arpeggio(X) +transpose(transpose(X,-7) ,4) ) +transpose(X,7) ) ,-7) |step((X+X) ,12) ) ) ,7) ) ,4) ,4) ) +transpose(shuffle(shuffle((shuffle(transpose(shuffle((arpeggio((X+X) ) +transpose(X,7) ) ) ,4) ) +(arpeggio(step(transpose((X+transpose(X,12) ) ,4) ,12) ) +echo(transpose(step((((transpose(X,-5) +transpose((X+transpose(X,7) ) ,7) ) +transpose((X+transpose(X,12) ) ,4) ) +transpose(((X+transpose(transpose(X,-7) ,4) ) +transpose(X,7) ) ,7) ) ,12) ,4) ,4,6) ) ) ) ) ,7) ) ,7) ) ,4) ,4) ) +transpose(((step((echo((step(X,12) |step(echo(arpeggio(X) ,4,6) ,12) ) ,4,6) +transpose((echo((transpose(step(X,12) ,4) |((transpose(transpose(X,4) ,-7) +transpose((echo(X,4,6) |((X+transpose(X,4) ) +transpose(X,7) ) ) ,4) ) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,7) ) ) ,4,6) |(((((arpeggio(X) |X) +transpose((X+transpose(X,7) ) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(shuffle(X) ,7) ) ,7) ) +transpose(echo(X,4,6) ,7) ) +transpose(((transpose(shuffle((X+transpose(transpose(X,-7) ,7) ) ) ,4) +transpose(transpose(echo((X+transpose(X,7) ) ,4,6) ,-5) ,4) ) +transpose(transpose(echo((X|X) ,4,6) ,4) ,7) ) ,12) ) ) ,7) ) ,12) +transpose((((transpose((arpeggio(echo(transpose(X,-5) ,4,6) ) |(((X|X) +transpose((X+transpose(X,12) ) ,4) ) +transpose((X+transpose(X,12) ) ,7) ) ) ,-7) +transpose(echo(transpose(arpeggio((X+transpose(X,7) ) ) ,4) ,4,6) ,4) ) +transpose((shuffle(echo(((X+transpose(X,4) ) +transpose(X,7) ) ,4,6) ) +transpose(arpeggio((transpose(X,-5) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ) ) ,12) ) ,7) ) +arpeggio(transpose((transpose(X,4) +transpose(arpeggio(X) ,12) ) ,4) ) ) ,-7) ) +transpose(shuffle(transpose(echo((arpeggio((shuffle(transpose((X+transpose(X,7) ) ,4) ) +((transpose(X,4) +transpose(transpose(((X+X) +arpeggio(X) ) ,-5) ,4) ) +transpose(((shuffle(X) +transpose(arpeggio(X) ,4) ) +transpose(transpose(X,-5) ,7) ) ,7) ) ) ) |echo(echo(transpose((echo(X,4,6) +transpose(transpose(arpeggio(X) ,4) ,7) ) ,-5) ,4,6) ,4,6) ) ,4,6) ,-5) ) ,12) ) ,7) ) ) )
random seed used was 0

NOTE: Generated phrase was too large ( 6219 ) , it has been truncated at 5000 notes. EXPR = arpeggio(transpose(arpeggio((((transpose(transpose(step(((((step(X,12) |((((X+transpose(X,4) ) +transpose(X,7) ) +transpose((X|X) ,4) ) +transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,7) ) ) +arpeggio((X+transpose(X,12) ) ) ) +transpose(((X+(X+X) ) +transpose((((X|X) +transpose((X|X) ,12) ) +transpose(transpose(arpeggio(X) ,4) ,7) ) ,7) ) ,4) ) +transpose((((X+transpose(X,4) ) +transpose(echo(X,4,6) ,7) ) |(transpose(X,4) |shuffle(X) ) ) ,7) ) ,12) ,-5) ,-5) |arpeggio((arpeggio(shuffle(transpose(((((arpeggio(step(X,12) ) +transpose(transpose(echo(X,4,6) ,-5) ,4) ) +transpose(((arpeggio(X) +transpose((X+transpose(X,12) ) ,4) ) +transpose(echo(transpose(X,-5) ,4,6) ,7) ) ,7) ) +transpose(((transpose(echo(X,4,6) ,4) +transpose(step(X,12) ,7) ) |((((X+transpose(X,7) ) +transpose(shuffle(X) ,7) ) +transpose(X,4) ) +transpose(arpeggio(transpose(X,4) ) ,7) ) ) ,4) ) +transpose(transpose(((step(echo(X,4,6) ,12) +transpose(X,4) ) +transpose(transpose(X,-7) ,12) ) ,-7) ,7) ) ,-7) ) ) +transpose(((transpose((echo(((X+transpose(X,7) ) |(X+X) ) ,4,6) +transpose(X,12) ) ,4) |arpeggio(transpose((X+transpose(X,12) ) ,4) ) ) +((transpose(transpose(transpose(((step(arpeggio(X) ,12) +transpose((X+transpose(step(X,12) ,12) ) ,4) ) +transpose(echo(X,4,6) ,7) ) ,4) ,-7) ,-5) +transpose((arpeggio((transpose(transpose((X+transpose(X,7) ) ,-5) ,-5) +shuffle(transpose(X,-7) ) ) ) |echo((((((X+transpose(X,4) ) +transpose(X,7) ) +transpose(step(X,12) ,7) ) +transpose(X,4) ) +transpose(echo(echo(X,4,6) ,4,6) ,7) ) ,4,6) ) ,4) ) +transpose((transpose((transpose(shuffle(X) ,4) +transpose(arpeggio(X) ,12) ) ,4) +transpose(arpeggio(arpeggio(X) ) ,12) ) ,7) ) ) ,12) ) ) ) +transpose(echo(transpose(echo(transpose(transpose(transpose(X,-5) ,-5) ,-7) ,4,6) ,-5) ,4,6) ,7) ) +((transpose((shuffle(((transpose(transpose((transpose((X|(X|X) ) ,4) |arpeggio((((((X+X) +transpose(X,4) ) +transpose(transpose(X,-7) ,7) ) +transpose(arpeggio(X) ,4) ) +transpose(step(X,12) ,7) ) ) ) ,-7) ,4) +transpose(echo(echo(shuffle((echo(transpose(X,-5) ,4,6) |((((shuffle(X) +transpose((step(X,12) +X) ,4) ) +transpose(X,7) ) +transpose(transpose(X,-7) ,4) ) +transpose((X|X) ,7) ) ) ) ,4,6) ,4,6) ,4) ) +transpose(((arpeggio(arpeggio(shuffle(X) ) ) +transpose(transpose(transpose(((step(transpose((X|X) ,-5) ,12) +transpose(shuffle(echo(echo(X,4,6) ,4,6) ) ,4) ) +transpose(((transpose(X,4) +transpose(((X+(X+transpose(X,7) ) ) +transpose((transpose(X,-7) |X) ,12) ) ,4) ) +transpose(arpeggio(transpose(transpose(X,-7) ,-5) ) ,7) ) ,7) ) ,-7) ,-5) ,4) ) +transpose(arpeggio(((echo(X,4,6) +transpose((transpose(X,4) +transpose((X|X) ,7) ) ,4) ) +transpose(transpose(X,4) ,7) ) ) ,7) ) ,7) ) ) +transpose(arpeggio(transpose(shuffle(((((echo(X,4,6) +transpose(transpose(X,4) ,4) ) +transpose(transpose(X,-7) ,7) ) +transpose(X,4) ) +transpose(echo(arpeggio(X) ,4,6) ,7) ) ) ,-5) ) ,7) ) ,4) +transpose(echo(step((((transpose(((((step(X,12) +transpose(X,4) ) +transpose(echo((X+transpose(X,12) ) ,4,6) ,7) ) +transpose(echo(X,4,6) ,4) ) +transpose(step(echo(transpose(X,-7) ,4,6) ,12) ,7) ) ,-7) +transpose(step(((echo(X,4,6) +transpose((X|X) ,12) ) +transpose(((transpose(X,-5) +transpose(X,4) ) +transpose(X,7) ) ,12) ) ,12) ,4) ) +transpose(transpose(transpose((shuffle((X+transpose(X,12) ) ) +shuffle(echo(X,4,6) ) ) ,-7) ,-5) ,7) ) +transpose(((step(X,12) |(X|X) ) |transpose(X,-5) ) ,-5) ) ,12) ,4,6) ,4) ) +transpose((echo((arpeggio(step(transpose(step(transpose(transpose(X,-5) ,4) ,12) ,-5) ,12) ) +transpose(transpose(step((step(X,12) +(((X+transpose(X,4) ) +transpose(X,7) ) +transpose(transpose(X,-7) ,7) ) ) ,12) ,4) ,4) ) ,4,6) |(((shuffle(step(arpeggio(shuffle(transpose(X,-5) ) ) ,12) ) +transpose(step(arpeggio(arpeggio(arpeggio(transpose(X,4) ) ) ) ,12) ,4) ) +transpose(step(((echo(shuffle(X) ,4,6) +transpose(arpeggio(shuffle(transpose(transpose(arpeggio(X) ,4) ,-5) ) ) ,4) ) +transpose(arpeggio(transpose(arpeggio((X+transpose(transpose(X,-7) ,7) ) ) ,4) ) ,7) ) ,12) ,7) ) +transpose((((transpose(step(((X+transpose(X,4) ) +transpose(X,7) ) ,12) ,4) +transpose((arpeggio(transpose(shuffle(X) ,-7) ) +(echo(echo(X,4,6) ,4,6) |shuffle(shuffle(X) ) ) ) ,4) ) +transpose(echo(arpeggio(transpose(X,-5) ) ,4,6) ,7) ) +transpose((transpose((step(X,12) +(((X+transpose(step(transpose(X,-7) ,12) ,7) ) +transpose(arpeggio(arpeggio(X) ) ,4) ) +transpose(((echo(X,4,6) +transpose(transpose(((X+transpose(X,4) ) +transpose(X,7) ) ,-5) ,4) ) +transpose(X,7) ) ,7) ) ) ,-5) +(((transpose(echo(X,4,6) ,-5) |((X+X) |(((X+transpose(X,7) ) +transpose(transpose(X,4) ,4) ) +transpose((X+X) ,7) ) ) ) +transpose(step(X,12) ,4) ) +transpose(((arpeggio(X) +transpose(X,4) ) +transpose((step(X,12) |arpeggio(X) ) ,7) ) ,7) ) ) ,12) ) ,7) ) ) ,7) ) ) ) ,4) )
random seed used was 0


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