This from the make blog, which I basically just have to admit I’m addicted to:

Wolf and Pig’s stop motion adventure

Basically what’s going on here is that they’re playing the Dr. Who theme (which has awesome vintage synth roots back in the 80’s BBC labs IIRC), through some extremely high voltage tesla coils.  The arcing becomes the transducer for the sound, as the audio signal is driving the coil’s arc system.  That’s a pretty big voltage change of course, +/- 1v to something like half a million or so?  Anyway, enjoy: