Cymatics (from Greek: κῦμα “wave”) is the study of visible sound and vibration, a subset of modal phenomena. Typically the surface of a plate, diaphragm, or membrane is vibrated, and regions of maximum and minimum displacement are made visible in a thin coating of particles, paste, or liquid. Different patterns emerge in the excitatory medium depending on the geometry of the plate and the driving frequency.
The apparatus employed can be simple, such as the old Chinese spouting bowl, or Chinese singing fountain, in which copper handles are rubbed and cause the copper bottom elements to vibrate. Other examples are a Chladni Plate or advanced such as the CymaScope, a laboratory instrument that makes visible the inherent geometries within sound and music.