Britney Spears' Las Vegas residency opens LAS VEGAS, Dec. 28 (UPI) -- Britney Spears debuted her new show as part of a two-year-long Las Vegas residency before a crowd of about 7,000 people at Planet Hollywood's The Axis theater. The 90-minute show features 23 songs from the pop diva's repertoire, opening with the will.i.am-produced hit, "Work Bitch," MTV reported Saturday. Spears worked her way through seven costume changes and three wigs during the act, which opened Friday and is scheduled to be repeated another 97 times over the course of two years at The Axis. The show, "Britney: Piece of Me," includes Cirque du Soleil-like acrobatics, a giant projection of will.i.am singing along to "Scream and Shout," and a massive tree, upon which Spears is perched during "Toxic," USA Today reported. On hand for Friday's debut show were Spears' parents and siblings and fellow singers Miley Cyrus, Katy Perry and Selena Gomez.