http://www.gizmag.com/onetesla-music-playing-tesla-coil-diy-kit/25640/?utm_source=Gizmag+Subscribers&utm_campaign=c3c4fee4c1-UA-2235360-4&utm_medium=email
MIT students figured a way to modulate the arcs from a Tesla coil! Scroll down to the video to watch!
I want one!