I haven't listened to any of them yet, but I am surprised by how few there are. There's only one Chopin-like piece, for instance. This causes me to worry: how many bad Chopin-like pieces did this thing spit out before coming up with a passable one? If there's still a human intelligence sitting there and sorting the good compositions from the bad ones, the program is significantly less impressive.
Some of the music generated: http://arts.ucsc.edu/faculty/cope/mp3page.htm