Cymatics is the science, or art of turning sound into form, “a looking glass into a hidden world”.
Cymatics is mostly done through a Chladni Plate, which is a speaker like device through which various sound frequencies are passed. With every change in pitch a different and often detailed pattern is naturally formed in the medium which happens to be placed on its surface. Be it sand, a single liquid like water, oil, or a mix of various density liquids, every medium creates unique patterns to sound, like the images below (also known as Chladni Patterns after German physicist and Musician Ernst Chladni).
Images courtesy of Cymatics.org
Cymatic rockstar Evan Grant is a creative technologist and explains the pattern making process in this interesting presentation below.