The mariachi orchestra emerged in the late 1700s or early 1800s in west-central Mexico. 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. The typical instruments of contemporary mariachi include the vihuela, a five-string guitar related to an instrument popular in the Spanish Renaissance; the guitarrón, a large, fretless six-string bass guitar; a standard six-string acoustic guitar; and violins and trumpets, which usually play the melody. Trumpets were not added until the early 20th century, but they are now more or less an essential element. Mariachi music initially consisted of local or regional sones (instrumental music), but, early on, performances began to include vocal elements.

Early mariachis dressed in peasant garb (usually white), though since the early 20th century male mariachi bands typically have worn traje de charro, the attire of the cowboys of Jalisco—matching uniforms with tight, ornamented trousers, boots, wide bow ties, sombreros, and short jackets. The traditional ensemble was all-male, but since the 1940s women have played an increasing role in mariachi performance, and by the early 21st century there were a number of all-female mariachi groups. Most female performers dressed either in a modified version of traje de charro or in china poblana, a traditional costume consisting typically of an embroidered blouse, a long colourful skirt, and a rebozo (shawl).