Britney Spears opened her debut show in Vegas this weekend, performing her first of about 100 concerts in the coming two years. But did Britney really perform? Some believe she may have been lip-syncing, even though her manager and a casino executive insist she is performing live.

Spears was indeed wearing a microphone throughout her show, but sources feel she wasn’t singing live–even during slow songs like Perfume, during which she sat down on stage.

“Piece of Me,” which is the name of Britney Spears’ Las Vegas show, will play at the Planet Hollywood Resort & Casino for the next two years. Lasting less than 90 minutes, it featured (at least during her first show) a taste of old-school Vegas entertainment along with the heavier beats of today’s music. The show reportedly has lots going on to distract those who might not have questioned whether or not she was actually singing while on stage.

Opening night certainly drew an A-List crowd. Selena Gomez, Miley Cyrus and Katy Perry were stationed front and center by the stage.

Soy excited to see @britneyspears baby bottle pop it off tonight at her grand opening @phvegas! We are coming in full lewks to support!

— Katy Perry (@katyperry) December 28, 2013

Only time will tell if Britney Spears has what it takes to keep fans entertained for a two-year run in Vegas. She’s definitely no Elton John or Celine Dion, but there’s something about Britney that everyone seems to love. Her dancing is second to none–and when that’s combined with catchy tunes and her incredibly sexy, dazzling costumes–it just might keep Las Vegas talking for a while to come.

Image via Wikimedia