Brazil Music Festival

Rihanna performs during the Rock in Rio music festival in Rio de Janeiro, Brazil, early Saturday Sept. 24, 2011. The festival, which runs through Oct. 2, includes Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Felipe Dana)

Rihanna performs during the Rock in Rio music festival in Rio de Janeiro, Brazil, early Saturday Sept. 24, 2011. The festival, which runs through Oct. 2, includes Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Felipe Dana)

Katy Perry performs at the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival which runs through Oct. 2 also includes performances by Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Felipe Dana)

British singer Elton John performs at the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival, which runs through Oct. 2, includes performances by Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Silvia Izquierdo)

Katy Perry performs at the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival which runs through Oct. 2 also includes performances by Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Felipe Dana)

Music fans attend a performance by Brazilian rock band Paralamas do Sucesso at the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival, which runs through Oct. 2, includes performances by Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Silvia Izquierdo)

Fans sing along with Brazilian singer Claudia Leitte as she performs during the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival, which runs through Oct. 2, includes performances by Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay. (AP Photo/Silvia Izquierdo)

Brazilian singer Claudia Leitte performs during the Rock in Rio music festival in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival, which runs through Oct. 2, includes performances by Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay.(AP Photo/Silvia Izquierdo)

Brazilian singer Claudia Leitte performs during the Rock in Rio music festival, in Rio de Janeiro, Brazil, Friday Sept. 23, 2011. The festival, which runs through Oct. 2, includes performances by Katy Perry, Rihanna, Stevie Wonder, Red Hot Chili Peppers, Metallica, Guns N' Roses and Coldplay.(AP Photo/Silvia Izquierdo)