The drum kit is a collection of percussion instruments that form the backbone of many musical ensembles. A typical kit includes a bass drum, snare drum, tom toms and a variety of cymbals such as hi‑hats, rides and crashes. Sound is produced when the drummer strikes the drumheads or cymbals with sticks, mallets or brushes. As a membranophone, each drum uses a stretched membrane whose vibration creates the audible sound.