Os Mutantes was formed in São Paulo, Brazil, in 1966 by two brothers, Arnaldo Baptista and Sérgio Dias Baptista and lead singer Rita Lee. In the 60s and 70s they were a part of the Tropicália movement which encompassed art forms such as theatre, poetry, and music. The movement was characterized by a combination of the popular and the avant-garde, as well as a fusion of traditional Brazilian culture with foreign influences.
The band broke up in 1978 but reunited with a new formation in 2006. Sergio Dias is the lone remaining founding member of Os Mutantes and their latest album is entitled Fool Metal Jack.