What is Mariachi?
Mariachi is a musical expression that dates back to at least 18th century in Western Mexico. It is a tradition that can be defined by eight socio-musical elements: mariachi instrumentation and texture, musical genres and subgenres, performance methods and styles, singing styles and forms, dance styles, performative space, performance clothing, and the word "mariachi". Each element has its own history, originated at varying moments in time and in different regions of the Western Mexican countryside, and some, if not all, had to converge in order for the mariachi tradition to become what it is.
In 2011 UNESCO recognized mariachi as an Intangible Cultural Heritage, joining six other entries on the Mexican list of that category

Modifications of the music include influences from other music such as polkas and waltzes, the addition of trumpets and the use of charro outfits by mariachi musicians. The musical style began to take on national prominence in the first half of the 20th century, with its promotion at presidential inaugurations and on the radio in the 1920s.