any of a class of musical instruments in which a stretched membrane vibrates to produce sound. Besides drums, the basic types include the mirliton, or kazoo, and the friction drum (sounded by friction produced by drawing a stick back and forth through a hole in the membrane).

According to shape, drums are classified as barrel, conical, cylindrical, footed, frame, goblet, long, vessel, and waisted. The names membranophone and idiophone (instruments whose solid, resonant body vibrates to produce sound) replace the looser term percussion instruments when an acoustically based classification is required. Compare aerophone; chordophone; electrophone; idiophone.