Alicia Keys did her thing, while newcomer Joss Stone celebrated her 18th birthday, sharing the stage with legend Donna Summer. And Matchbox 20 front man Rob Thomas rocked it with Rod Stewart and company -- all for VH-1's "Save the Music Concert," benefiting music programs in America's public schools.

But it seems even music's biggest stars are into "Idol" worship, as the performers turned to their favorite topic: "American Idol."

"Sometimes I catch it, and we have a good time just watching and checking it out," Keys admitted. "It's always fun to see something that's a little competitive in spirit."

Meanwhile, the guys from The Goo Goo Dolls liked to boo Simon. "I like Paula Abdul, but I hate that guy," one member said. "He should be deported."

And Rob Thomas, who is celebrating the release of his new solo CD, revealed he's rooting for Scott Savol to win the competition: "I like the big guy. He's got that cool New Orleans kind of vibe."

And before "Idol" contestant Mario Vazquez mysteriously dropped out of the competition, Rob even sent text messages about him to host Ryan Seacrest. "I'm friends with Ryan," Thomas said. "I would send Ryan little messages saying, 'Man, where's that kid? I love that kid?'"