Britney Spears Could Be Forced To Have Psychiatric Examination in Ex-Manager's Lawsuit
Britney Spears Could Be Forced To Have Psychiatric Examination in Ex-Manager's Lawsuit

Britney Spears has been posting 20-second previews of new songs over the past two weeks, but the latest preview of seventh full-length "Femme Fatale" has leaked in its entirety. "Till the World Ends" hit the web this afternoon (Mar. 3), and hours later, Spears wrote on Twitter, "Looks like the cat's out of the bag..."

"You notice what I'm wearing/I'm noticing your staring/You know that I can take it/To the next level baby," Spears sings over a slithering beat that recalls past hits by Taio Cruz, Robyn and Enrique Iglesias. The energy ramps up in the kinetic refrain, where the pop star joins a vocal chorus and commands the listener to "dance until the world ends."

"Till the World Ends" arrives after Spears and "Fatale" executive producer Lukasz "Dr. Luke" Gottwald posted snippets of album cuts like "I Wanna Go," "Seal It With a Kiss" and "Inside Out" on Twitter beginning Feb. 20. On Monday (Feb. 28), Black Eyed Peas frontman Will.i.am posted a preview of "Big Fat Bass," a collaboration with Spears that may appear on the album.

While the leaked track sounds close to a finished product, Spears took to Twitter and promised to play a final version of "Till the World Ends" tomorrow morning (Mar. 4) on Ryan Seacrest's syndicated radio show. Fans can also hear "World" when "Femme Fatale" is released on Mar. 29; Spears calls her latest full-length "the best album I've ever made" in the new issue of V Magazine.

Jive Records, Spears' label, has confirmed they are rush-releasing the song to the iTunes store tomorrow (Mar. 4). Does that mean she'll instantly debut at No. 1 on the Billboard Hot 100 next week -- following the chart-topping bows of her last two singles, "3" and "Hold It Against Me?" We'll know for sure next Wednesday morning (Mar. 9), when we compile the new week's chart. "Hold It Against Me" premiered at No. 1 on the Hot 100 after it hit digital retailers on Jan. 10.

It began with 411,000 downloads sold, according to Nielsen SoundScan -- at that point the biggest debut sales week for a woman. (A record since eclipsed by Lady Gaga's "Born This Way," which arrived with 450,000.)

(Additional reporting by Keith Caulfield.)