CYMATICS: Science Vs. Music - Nigel Stanford
'Cymatics' is the science of visualizing audio frequencies. All of the experiments are real.
This video is amazing! It shows how audio can interact with the environment, resulting in some awesome visuals. I particuarly liked the water, but the van de graaff generator was pretty great too. Created by Nigel Stanford and is a must watch!
Watch the video
There is also plenty of Behind The Scenes videos if you were wondering how it is all done.