The Grammy Awards brought some of the biggest names in music together in LA last night, but the afterparties got those stars in a celebratory mood. Rihanna changed out of the custom Azzedine Alaïa frock she wore to the big event and into a belly-baring white dress to attend an afterparty at the Supperclub with Chris Brown. Meanwhile, Justin Timberlake hosted a private event at the Hollywood Palladium, where he performed in front of an excited crowd. His post-Grammys show would mark one of several gigs that night — he also made a splashy return to performing on TV at the Grammys earlier that evening. Justin and Rihanna's parties weren't the only big shindigs for the night. Selena Gomez, Katy Perry, John Mayer, and Lena Dunham were all spotted enjoying the town after the Grammys festivities.