Prince popped up as a surprise guest around midnight at In Style magazine's party following Sunday's awards show. He played guitar on "Brickhouse" and his signature hit "Kiss," but left the singing to the band.
After two songs, he blew a quick kiss to the crowd and hopped off the stage.
Nick Lachey stood on a pink-cushioned bench near the back of the room to get a look as his wife, Jessica Simpson, hurried down front. Alicia Silverstone, Kevin Costner, Jim Belushi, Lance Bass and Clint Eastwood were among those who attended the party.
Paris and Nicky Hilton attracted gawkers while making the rounds of several parties at the Beverly Hilton. The hotel was once owned by Barron Hilton, the sisters' grandfather.