Girl Power

What exactly does it take to get the planet's hottest pop music divas -- Mariah Carey, Beyonce, Mary J. Blige, Rihanna, Fergie, Sheryl Crow, Miley Cyrus, Melissa Etheridge, Ashanti, Natasha Bedingfield, Keyshia Cole, Ciara, Leona Lewis, LeAnn Rimes, and Carrie Underwood -- to collaborate on a song? The answer is the fight against cancer. "Just Stand Up," a project conceived by industry heavyweight Antonio "LA" Reid and co-produced with longtime collaborator Kenneth "Babyface" Edmonds, hits airwaves and iTunes Sept. 2. All sales of the song will benefit cancer research and all 15 singers will take the stage together on Sept. 5 to perform the song live on the "Stand Up to Cancer" television special, which airs simultaneously on all three major networks.