Argentinean singer/songwriter Miguel Mateos became involved in the local music scene as leader of the band Cristal. Along with his brother Alejandro Mateos and musicians Jorge Infusino, Ricardo Pegnotti and Fernando Lupano, the talented artist formed a band called Zas in 1979. The group appeared live as opening act for British rock legends Queen in February of 1981. A self-titled debut album was released in 1982, followed by Huevos in 1983. By that time, bassist Raúl Chevalier and guitarist Eduardo Sanz joined the band. After issuing Tengo Que Parar in 1984, Miguel Mateos y Zas hit local charts with a song called Tira Para Arriba. Soon after, a live recording was made at Buenos Aires' Coliseo Theater, later released as Rockas Vivas. The success of that record allowed Miguel Mateos to perform four acclaimed shows at Buenos Aires' Luna Park, one of the most important local venues. The following year, the group played in the U.S., this time with guitarist Carlos García and bass player Cachorro López; the result was Solos en America, a Latin rock masterpiece. During the 1990s, Miguel Mateos made the decision to settle in Miami, where the artist made four solo records. In 1998, keyboardist Mario Maselli and bassist Ariel Pozzo joined the new band's lineup, recording Bar Imperio.