Mariachi was heavily involved in cultural promotion as a way to create a unified Mexican identity after the end of the Mexican Revolution. One of these efforts was the promotion of mariachi as an international symbol of Mexican identity, first with radio and sound recordings and later with films. Mexico built a nationwide radio broadcasting network in the 1920s such as XEB and XEW, which began broadcasting mariachi music as a media production, rather than as a music for social events. This music was already being modified in part due to the advent of sound recording. For example, most son jaliscense
Mariachi varies depending on the availability of musicians. The usual mariachi group today consists of as many as eight violins, two trumpets and at least one guitar. Traditional mariachi guitars include the vihuela, a high-pitched, round-backed guitar that provides rhythm, and a bass guitar called a guitarrón, which also provides rhythm. Sometimes a Mexican folk harp provides bass and ornaments the melody. All are Mexican variations of European instruments. There is generally no lead singer as in other kinds of group with all players singing choruses and taking turns singing the lead. Often the lead singer is assigned to a certain