Parties! The style, stars and scoop from Hollywood's hottest events

Christina Aguilera got the party started at Clive Davis' annual pre-Grammy bash, held at the Beverly Hilton hotel in L.A. The Grammy-nominated songstress performed recent hits like "Candy Man" for a crowd that included Nick Lachey and Vanessa Minnillo, Sean 'Diddy' Combs, Katharine McPhee, Ashlee Simpson and John Mayer. A few of the lucky guests had also attended the Justin Timberlake pre-Grammy concert the night before.

—Brantley Bardin

Check back with InStyle.com for complete coverage of the 49th annual Grammy awards.