'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.