Originally from Fresnos, Apodaca, a municipality belonging to the state of Nuevo León, 821 has been giving music hard and thick for several years, consistently releasing singles, videos and long-term productions. Under Side 821 is a rap collective made up of Doer, Pollo, Antuan, Bolado, Oso, Basher, Luzio and Nonefield. As they themselves have published on their networks: “We are not THE UNDER SIDE because we are not a musical group or a group, much less a soloist. We are THE UNDER SIDE because we are a click, a gang, a bargain, a family, a gang. ”
They have released a large number of classics since their beginnings in 2008, such as "Sangre de Barrio", "La Cumbia de la Lluvia", "El Soldado" or "Los Caídos". In August 2012 they recorded La Lotería, an interesting full-length production that is one of the few conceptual albums that have been made in Mexa rap: based on the cards of the popular game, themes such as the pot, the rose, the lady, fish, among others, are used to tell different stories that refer to their daily lives.