This is a great look at how sound waves behave. Not a visualization, but actual images of the sound waves. Pretty cool.
A few years ago I met a Chet Udell at a SEAMUS conference. He is a composer/technologist, a nice guy, and he wrote a great piece for trombone, piano and computer stuff. We have kept in touch, mostly via running into each other at conferences and whatnot.
Last fall, I saw him do a demo of a new gesture control system that he has been developing, and the possibilities were pretty exciting.
He is nearing the end of the Kickstarter for it. If you are curious about that sort of thing, check it out.
Visit the page here: http://kck.st/1gTwSCF