The Most Star-studded Single Ever?

Could this be the most star-studded single of all time?

Fifteen (!) of the biggest female names in pop music are going to squeeze on to one charity single to support the Stand Up To Cancer campaign.

Just Stand Up, produced by Babyface, will feature (deep breath) 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.

Wow.

And they're going to perform it live on the Stand Up To Cancer television special, which will make television history on September 5th by being broadcast simultaneously on ABC, NBC and CBS during primetime.

Other stars expected to turn out for the hourlong show include Jennifer Aniston, Lance Armstrong, Katie Couric, Sally Field, Salma Hayek, Meryl Streep, Forest Whitaker and Reese Witherspoon, according to NYTimes.com.

All sales of the track, available on iTunes from September 2, will go towards cancer research.