Britney Spears  was back in fine form when she hosted the Wango Tango music festival in Carson, CA, yesterday. She was joined by her former kindred X Factor judge Demi Lovato as well as performers Avril Lavigne , Bruno Mars, and Maroon 5's Adam Levine. Britney wore a formfitting black dress as she took the stage to introduce the acts, marking her first onstage appearance since she left The X Factor back in January. While she didn't perform this time around, Britney fans will get a chance to see the singer perform live soon as she confirmed last week that she will be taking up a residency in Las Vegas . The concert series, which will reportedly be held at Planet Hollywood, will begin in the Fall. Preparing for Sin City isn't the only thing on Britney's mind — she recently tweeted that she is reading The Goddess Inheritance, a YA novel by Aimee Carter.
Britney Spears  wore a black dress.
Britney Spears  worked her stuff on the red carpet.
Adam Levine performed with Maroon 5.
Avril Lavigne  performed at Wango Tango.
Demi Lovato wore a sheer top.
Bruno Mars rocked a retro look.
Victoria Justice wore a printed dress.