Lamere built The Autocanonizer at the SXSW Music hackathon using technology from The Echo Nest. It tranforms any song into a canon by simultaneously playing multiple parts of the song that sound good together. There’s also a pretty cool visualization of what’s playing.
The Autocanonizer doesn’t always work, and it’s best to choose a song that’s not too complex. London Grammar’s “Hey Now”and most Grimes songs worked pretty well for me, as they’re mostly comprised of chords, vocals, and drum machines.