Brazil's Caetano Veloso and Gilberto Gil play together

Brazilian music would probably not have developed as it did over the past decades years if not for Caetano Veloso and Gilberto Gil, two of the country's most important musicians.

They revolutionised Brazilian music in the late 1960s with the Tropicalia movement, embracing foreign influences and experimenting with different musical styles.

Now at age 72, they are still far from retiring and are setting off on their first tour together since 1994.

Veloso and Gil performed Nine Out of Ten together for the BBC.