Thanks Bridgetta.(requires Flash) If you want to see how this works and spoil the illusion here is how it works
Amazing Music Synth University of Iowa (Thanks Bridgetta) This machine was built as a collaborative effort between the Robert M. Trammell Music Conservatory and the Sharon Wick School of Engineering at the University of Iowa. 97% of the machine's components came from John Deere Industries and Irrigation Equipment of Bancroft, Iowa, yes farm equipment!