LOS ANGELES (AP) - What would it sound like if 15 of the hottest female singers joined voices? The answer will be revealed Sept. 2.

That's when "Just Stand Up" hits airwaves and iTunes. The song features 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. All sales of the star-studded single will benefit cancer research.

The charity tune was conceived by Antonio "L.A." Reid, who produced it with longtime creative colleague Kenny "Babyface" Edmonds.

All 15 singers will share the stage to perform the song live on Sept. 5 during the "Stand Up to Cancer" television special, set to air simultaneously on ABC, NBC and CBS. Other stars expected to turn out for the hourlong fund- and awareness-raising program include Jennifer Aniston, Lance Armstrong, Katie Couric, Sally Field, Salma Hayek, Meryl Streep, Forest Whitaker and Reese Witherspoon.

Founded in 2007, Stand Up to Cancer is a program of the Entertainment Industry Foundation that calls on entertainment-industry people and platforms to help fight cancer.

Click the pics for Mariah Carey's gallery:

Click the pics for Miley's gallery:

Click the pics for Beyonce's gallery:

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