Complex sentence: The band was very successful in the mid- 1980s, being considered the Rolling Stones of Brazil: the live album Rádio Pirata ao vivo was the best-selling ever recorded in Brazil with more than 2.2 million copies sold.
Split into simpler sentences: The band was very successful in the mid- 1980s, being considered the Rolling Stones of Brazil. Their live album "Rádio Pirata ao vivo" was the best-selling Brazilian record ever, with more than 2.2 million copies sold.