Japanese artist Kenichi Kanazawa visualizes sound by manipulating multicolored sand atop a steel tabletop. The study of visible sound is apparently known as cymatics and, in this case, is demonstrated by a rubber mallet that creates vibrations, moving the grains of sand to create beautiful and colorful patterns.
Amazing Chladni Plate Experiment
This is the Chladni plate experiment. Specific frequencies vibrate the metal plate so that it creates beautiful geometric patterns.