The Guitar is probably the most recognized instrument in the world. The Guitar in the mariachi ensemble is very important because it supports the rhythmic pulse along with the Guitarrón and Vihuela Mexicana. The Guitar used in the mariachi ensemble is an acoustic classical guitar with nylon strings. The Guitar provides a wider range of pitch to give the ensemble a full rich all-around tonality. The Guitar has 6 strings which are tuned (from 6th to 1st) E-A-D-G-B-E. It has 3-nylon monofilament strings and 3-wound strings with a synthetic core. The Guitar is a fretted string instrument using metal strips for the frets. The Guitar has the capability of utilizing at least 12 frets on the fingerboard thus giving it a wider range of pitch and desired chord formations. (The Vihuela Mexicana and the Guitarra de Golpe are limited to 5 - 7 frets.) The body or the "resonating chamber" is bigger and wider than a Vihuela Mexicana and the Guitarra de Golpe.
In 1850, a Spanish luthier named Antonio de Torres Jurado, designed a classical guitar type that is now a standard design in modern acoustic classical guitar making. It is also called a Spanish Guitar. The optimal design for a guitar used specifically for the mariachi ensemble could be that the body be bigger and wider than a standard acoustic classical guitar, and that the action be as such so that when vigorously strumming the mariachi rhythms, that there is no buzzing or unwanted vibrations from the strings.
We usually do not play a melody with the Guitar but if an arrangement calls for a particular bass or melodic line, the guitar is very capable. Its main role is for the Guitar to be strummed and act as a percussive instrument with pitch.
The role of the Guitar functions as the secondary support instrument to the Guitarrón and the Vihuela Mexicana of the mariachi ensemble. It provides the rhythmic, syncopated pulse and musical guide along with the Guitarrón and the Vihuela Mexicana. (These instruments together are commonly referred to as the rhythm section or las armonías.)