That's a hoot. Back in the 60's, I took a nuclear physics class and we had a multichannel analyzer from Nuclear Data that could output its data to a bar of solenoids like on that piano. We bolted the whole thing to the department secretary's IBM Selectric typewriter and the solenoids pressed the keys on the typewriter, delivering a page full of numbers. Of course, it was fascinating to watch.This one is quite interesting - I understood the piano far better than I understood the humans in the video, as nein sprecken ze Deutch...
http://www.wimp.com/talkingpiano/