Please, don't call him 'El'

Please, don't call him "El". That's like calling The Spider-Man "The".

At least, call him the Mariachi, since THE MARICHI means EL MARIACHI.

See:

EL = THE
MARIACHI = MARIACHI

Anyways, mariachi is the name of a music group who plays, well, Mariachi music.
The group MUST include at least 3 guitar players. 4 violin players. One 'guitarron'(literally The Big Guitar, it works as a six-string bass guitar). One or two "Vihuela"(no translation, it is a different kind of guitar) and 4 trumpets. A main singer sings, and the whole group sings in the chorus.

Large groups may include harp, viola, 'jarana'(a smaller guitar), and in very weird cases, various metal instruments(like sax or horns).

Also, it's important to note that, while the mariachi music os probably the best-known form of mexican music, it is only the music of one state: Jalisco. In other states there is very different music to hear.

To a new world of gods and monsters!
- Dr. Pretorius, Bride of Frankenstein