Os Mutantes, the teenage house band for Brazil's revolutionary tropicalia movement, were a late 60s phenomenon. Playing fuzzed-out rock'n'roll on homemade instruments, São Paulo brothers Sérgio and Arnaldo Dias Baptista and their friend Rita Lee brought a surreal playfulness to the incendiary mood of a country living under a dictatorship, before an excess of LSD and free love triggered their collapse.

Rita Lee jumped ship in 1972, going on to become Brazil's most successful exponent of brega (bad taste) rock. Arnaldo left a year later, shortly before jumping from the third floor of a psychiatric hospital, leaving him in a coma for six weeks. Sérgio Dias soldiered on in an increasingly progressive rock vein before calling it quits in the late 70s.

In the decades that followed cult interest in the band grew, leading to reconciliation between the estranged Baptista brothers and a string of successful reunion concerts in 2006 and 2007 – albeit with the Brazilian singer Zélia Duncan taking the place of Rita Lee. It wasn't to last. Arnaldo, in fragile mental health, quit after the first batch of performances, leaving guitar-toting younger brother Sérgio to carry the banner single-handedly once more.

Now comes the first album of new material for 35 years, and although never quite reaching the innocent glory of late 60s Mutantes, Haih or Amortecedor is still brimming with vitality and ideas. Querida Querida, with its harmonised vocals, screaming riffs and mood of slightly paranoid urgency, is reminiscent of Os Mutantes' 1970 stoned classic A Divina Comédia ou Ando Meio Desligado. Tropicalia was always concerned with filtering political issues through artistic lenses, and Baghdad Blues is an exotic ode to Saddam Hussein that, with its shouts and parping trumpets, does not ask to be taken too seriously.

Without the mischief of Rita Lee or the surrealism of Arnaldo Baptista to keep him in check, Sérgio Dias has in the past run the danger of disappearing into a jazz odyssey. There are moments of ultra-complex pointlessness here, but on the whole Dias manages to resist the urge to show off. There's nothing to match Mutantes masterpieces such as Bat Macumba or Baby, but then they were versions of songs by Gilberto Gil and Caetano Veloso: the band's real genius was in the strange sounds they created rather than the songs they wrote. And Gopala Krishna Om has the reverberating buzz of the sewing machine-powered guitar that gave Bat Macumba its unique flavour. The spirit of the mutants lives on, in other words, and that is cause to celebrate.