Formed in Brazil in 1966, Os Mutantes were one of the wildest and most beloved bands in the Tropicália movement, which combined traditional Brazilian styles with North American soul and psychedelia. Between 1968 and 1974, Os Mutantes recorded eight albums, including two that wouldn't be released until decades later, that explored everything from jazz to progressive rock, always with a distinctly Brazilian edge. After being rediscovered by adventurous indie rockers in the '90s, Os Mutantes reunited (minus original singer Rita Lee), releasing the album Haih or Amortecedor in 2009.