The best scholarly opinion is that the word mariachi has native roots. One theory is that it comes from the name of the wood used to make the platform on which the performers danced to the music of the village musicians. But whatever its true source - and the truth may never be discovered with absolute certainty - the word today has one meaning that is crystal clear: Mariachi means one of the most exciting and enchanting musical ensembles found anywhere in the world.

The instruments, the attire, and the music help distinguish mariachis from other musicians. Most mariachi groups average between seven and nine members. The music and style define what mariachi really is. Mariachi groups have an almost universal repertoire of songs native to the genre, such as Cielito Lindo, Jalisco, El Son de la Negra, and El Rey. Shouts and cries given at certain times are called "gritos," and are essential to the character of the music.

The attire of a mariachi group, called a "traje," consists of botines (ankle boots), a sombrero (broad-rimmed hat), moño (large bow tie), chaleco (short jacket), snug trousers without back pockets, a wide belt, and botonaduras (shiny buttons) on the sides of the pants.