Bongos (Spanish: bongó) are an Afro-Cuban percussion instrument consisting of a pair of small open bottomed drums of different sizes. In Spanish the larger drum is called the hembra (female) and the smaller the macho (male). They are membranophones, or instruments that create sound by a vibration of 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. 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".
The origin of the bongo is largely unclear. Its use was first documented in the Eastern region of Cuba known as the "Oriente", during the 19th century, where it was employed in popular music styles such as Cuban son, Nengon, and Changui.