Corinne Bailey Rae performs at Wembley stadium in London as part of the Live Earth concert marathon to raise awareness about climate change on July 7, 2007.
Anthony Kiedis of the Red Hot Chili Peppers performs at Wembley stadium in London as part of the Live Earth concert marathon to raise awareness about climate change on July 7, 2007.
John Legend, left, and Corinne Bailey Rae sing a duet of Marvin Gaye's socially-conscious song "Mercy Mercy Me (The Ecology)" from 1971 at the London Live Earth concert at Wembley stadium on July 7, 2007.
The Beastie Boys perform at the Live Earth concert in London held at Wembley stadium on July 7, 2007. The concert was one of a series spread over 7 continents including a performance by a band made up of a group of scientists stationed in Antarctica.
Comedian Chris Rock introduces one of the performers at the London leg of the Live Earth concerts on July 7, 2007, held at Wembley stadium.
Duran Duran pose backstage at the Live Earth concert in London held at Wembley stadium on July 7, 2007.
Bassist Flea of the Red Hot Chili Peppers performs at Wembley stadium July 7, 2007 in London as part of the 24-hour global Live Earth event to raise awareness of climate change and the environment.
Geri Halliwell -- a.k.a. Ginger Spice of the 1990s pop juggernaut the Spice Girls -- appears on stage at the Live Earth concert at London's Wembley stadium July 7, 2007.
Singer-songwriter James Blunt performs at London's Wembley stadium as part of the Live Earth concert marathon to raise awareness of climate change issues on July 7, 2007.
Madonna performs with her dancers at Wembley stadium during the London leg of the Live Earth 24-hour concert marathon on July 7, 2007. Part of her performance was aired before the crowd at the New York area concert held at The Meadowlands in East Rutherford, N.J.
Scottish singer-songwriter Paolo Nutini sings at the Live Earth concert at Wembley stadium in London on July 7, 2007. Nutini performed Louis Armstrong's signature song "It's A Wonderful World."
There doesn't seem to be any energy crisis when it comes to the Black Eyed Peas' performance, as they tear up the stage at the London leg of the Live Earth concert marathon on July 7, 2007.
The Pussycat Dolls loosen up their buttons, baby, during their performance at Live Earth in London on July 7, 2007.
Faux rockers Spinal Tap recreate the hilarious Stonehenge scene from their classic mockumentary at the Live Earth concert in London held at Wembley stadium on July 7, 2007.
Phil Collins of British rock group Genesis performs on stage during the Live Earth concert held at Wembley Stadium on July 7, 2007 in London.