Each of the five new stamps in the pane of 20 features a musician, dressed in the traditional outfit of mariachi performers, playing one of five iconic mariachi instruments: guitar, guitarrón, vihuela, violin and trumpet. The geometric shapes in the background of each stamp are a nod to Mexican villages, where mariachi music originated.

“Mariachi” refers to several things: to the music itself; to an individual musician or an ensemble of musicians; and, when used as an adjective, to anything identified with the music — be it dance or costume or culture. The first known written reference to the word “mariachi” was made in the 1850s, but the music’s roots stretch back long before.

Though mariachi’s exact origins are obscure, it appears to have begun in western Mexico, where itinerant musicians made their living traveling from village to village and visiting ranches in the countryside to perform. The music of early mariachi included folk traditions from Spain, Mexico and Africa that melded to create a new indigenous musical form, the son. The sones developed in various regional styles, including the son jalisciense from Jalisco; the son huasteco, from northeastern Mexico; and the son jarocho or veracruzano, from the region around the Gulf port of Veracruz. The most well-known example of the son jarocho is the song “La Bamba.”

Beginning in the 1930s, mariachi music reached a new, wider audience as it was embraced by urban radio stations and used on soundtracks by Mexican filmmakers. It soon became one of the most popular musical genres in Latin America.

Mariachi bands traditionally used the round-backed guitar called the vihuela, which gives the mariachi music its rhythmic vitality; the guitarrón, which is a bass guitar; and the Mexican folk harp, the arpa. By the 1940s and 1950s, the modern urban mariachi sound emerged with the expanded instrumentation including violins and trumpets. Today, ensembles continue to broaden the use of instruments, with some groups adding six to eight violins, two to four trumpets, an accordion, and the arpa, which had fallen out of use but has made a comeback among professional groups. This combination of instruments creates a unique music that is exuberant and expressive.

While mariachi music had been in the United States for many years, by the 1960s, American churches, schools and universities began to develop and sponsor mariachi programs that produced new generations of musicians and enthusiasts. Immigrants to various parts of the United States created vibrant regional mariachi cultures that widened the appeal of this traditional music to new audiences. In addition, the American mariachi movement is being disseminated by first-, second- and third-generation Mexican Americans as a way of expressing ethnic pride and of staying connected to their heritage.

Mariachi musicians are immediately recognizable in their traditional costume called traje de charro or charro suit. An adaptation of a Spanish horseman’s riding outfit, it consists of fitted trousers adorned with silver buttons for men and full-length skirts for women, a short jacket, an embroidered belt, a wide bow tie, and a wide-brimmed hat. Though black with silver embellishments is traditional, today mariachi wear costumes in many colors.

A beloved aspect of mariachi culture is dance, as this is music that is meant to get audiences moving. Each of the regional variations of the son has its traditional style of dance. While several dance styles are favored by mariachi fans, the most well-known folk dance is the Jarabe Tapatío — the Mexican Hat Dance. Highly stylized with traditional steps and movements, it is the national folkloric dance of Mexico. This dance made its way from Mexico to the United States, where it is popularly celebrated at festivals and public performances and in dance competitions. Enjoyed around the world, mariachi has reached a global audience through recordings, films, live concerts, and television programs.

In recognition of the importance and widespread appeal of mariachi music and culture, UNESCO added them to its Intangible Cultural Heritage of Humanity list in 2011.