Warwick said the show never initiated talks with Prince and doesn't really need to go looking for stars.
"There's a queue from the record companies, as you can probably imagine because we have 30 million people-plus each week tune in, and so we don't need to go hunting, as it were," he said.
"American Idol's" ratings are up 14 percent over last year, which Warwick attributes to the contestants.
"We've got a soul singer, a rock singer, a country singer, a Barbra Streisand (type), we've got a crooner," he said. "It's that diversity, I think, that keeps people interested. This year more than ever, the public have really hooked into these kids."