Producer Quincy Jones says putting together a lineup of performers and presenters for his benefit concert in Rome Sunday was a giant task.

Norah Jones, Alicia Keys, Andrea Bocelli, Muhammad Ali, Angelina Jolie and Oprah Winfrey are among those expected to participate in the We Are the Future concert. The event will raise money for child centers in Ethiopia, Eritrea, Sierra Leone, Afghanistan, Rwanda and the West Bank.

"We've got some more surprises coming up, too. You'll see. Some good ones," Jones says. "It's always like that. You never know. Man, please! It's like trying to saddle a rat to try to lock everybody down. Their lives change all the time."

The concert, which will be held at the ancient Roman chariot track Circus Maximus, will be broadcast by MTV at a future date.