Bongo or bongos are a percussion instrument consisting of a pair of single-headed, open-ended drums attached to each other. The drums are of different size: the larger drum is called in Spanish the hembra (female) and the smaller the macho (male). It is most often played by hand and is especially associated in Cuban music with a steady pattern or ostinato of eighth-notes known as the martillo or "hammer". They are membranophones, or instruments that create sound by a vibration against a stretched membrane.
Bongo drums produce relatively high-pitched sounds compared to conga drums, and should be held behind the knees with the larger drum on the right when right-handed. They are traditionally played by striking the edge of the drumheads with the fingers and palms, although some contemporary compositions require drum sticks. Bongos can also be muted by placing part of the hand on top of the head while striking it. In Cuban music, bongos are usually played by the same musician as the cowbell (Spanish: cencerro). These drums can also be played on a stand, as is the case with concert orchestras and bands.
The moose call or glissando is done by rubbing the third finger, supported by the thumb, across the head of the drum. The finger is sometimes moistened with saliva, or sweat before rubbing it across the head. most bongo players may use beeswax to help make the sound.