Mariachi is a small Mexican musical ensemble composed of a variety of mostly stringed instruments. In addition to referring to an ensemble, the term mariachi is also used for the individual performer of mariachi music or for the music itself. Mariachi has long been considered a uniquely Mexican sound, representing a homegrown tradition that embraces both indigenous and foreign elements. The word mariachi may have come from the now-extinct language of the Coca Indians, but both the word’s etymology and the early history of the form and its followers are unknown.

Source: Britannica