Mariachi politics, revolutionary heroes and even animals and country life from the genre origins as rural "son" music. One particularly famous song is “La Cucaracha” (The Cockroach). Most mariachi groups are associated with family and religious celebrations along with serenades. One of the most common pieces played by Mariachis is “Las Mañanitas” for birthdays and celebrations of patron saints. In Mexico, mariachi music can also be found as part of Catholic Mass. The Misa panamericana is a mariachi folk mass sung in Spanish with new arrangements of classic hymns such as "Kyrie Eleison". This innovation began in 1966 by Canadian priest
Mariachi problems recruiting mariachi instructors as many of these do not have required teaching credentials. For this reason, schools often hire trained musicians from outside the mariachi tradition. Many traditional mariachis are concerned that standardization will lead to fossilization and restrict improvisation. Other innovations in the United States have been the incorporation of styles of artists such as Elvis Presley, Freddy Fender and Glenn Miller, as well as the heavy-metal Mariachi band Metalachi. Another is the encouragement of female mariachis including all-female Mariachi groups such as Mariachi Mujer 2000 and Mariachi Divas de Cindy Shea. Mariachi Mujer has performed with Mexican