The banjo is a four-, five-, or six-stringed instrument with a thin membrane stretched over a frame or cavity as a resonator, called the head, which is typically circular. The membrane is typically made of plastic, although animal skin is still occasionally used. Early forms of the instrument were fashioned by Africans in the United States, adapted from African instruments of similar design.[1][2] The banjo is frequently associated with folk, Irish traditional, and country music. Historically, the banjo occupied a central place in African-American traditional music and the folk culture of rural whites before entering the mainstream via the minstrel shows of the 19th century.[3][4][5][6] The banjo, along with the fiddle, is a mainstay of American old-time music. It is also very frequently used in traditional ("trad") jazz.