Cymatics is a subset of modal vibrational phenomena. The term was coined by Swiss physician Hans Jenny (1904–1972). 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.

A standing bell or resting bell is an inverted bell, supported from below with the rim uppermost. Such bells are normally bowl-shaped, and exist in a wide range of sizes, from a few centimetres to a metre in diameter. They are often played by striking, but some—known as singing bowls—may also be played by rotating a suede covered mallet around the outside rim to produce a sustained musical note.