Drum (Dan. trom; Ger. Trommel), in music, a hollow cylinder of thin wood or brass, covered at each end with vellum or parchment, the tension of which is regulated by small cords or braces on the outer side of the instrument acted upon by sliding knots of leather. The common drum is suspended at the side of the drummer, whence it is called the side drum, and is beaten upon at one end with sticks. An instrument similar in shape, but on a much larger scale, called the base drum, is beaten at both ends with drumsticks having leather pads on the knobs. Both kinds are highly effective in military bands. Another species, called the kettle drum, consists of a thin copper basin, nearly hemispherical, the parchment covering of which is held by an iron rim, and tightened or relaxed by screws. Kettle drums are always in pairs, one instrument being tuned to the key note, and,the other to the fifth of the key. They are generally supported on iron tripods. Instruments of percussion of the drum species have been familiar in the East from remote ages, and among savage races in all parts of the world are used in the celebration of religious rites as well as for the performance of music.

They were common among the Egyptians, chiefly for military music, as early as 1000 B. C, some being long cylinders, similar to the tomtoms of India, which were beaten with the hand, while others were of a barrel shape and were beaten with sticks. Among the Greeks and Romans the drum, called the tympanum, had the form of the modern kettle drum or of the tamborine. The drum was probably introduced into Europe by the Saracens and Moors, by whom it was called the tumour, whence the Spanish tambor and the French tambour; and in the first half of the 14th century it was generally adopted for military music.