Britney Spears' 27th Birthday Bash

Britney Spears had a whirlwind birthday on Tuesday that started with a wild performance on "Good Morning America," marking the release of her sixth studio album, "Circus," and the continued later that night with a celebration at New York City's Tenjune nightclub where Access Hollywood was on the scene.

Brit's 27th birthday bash was so exclusive that there was not one, but two VIP areas -- the second was within the first and guarded by three security people. But, the tight security did not stop a slew of stars from showing up to help the pop star celebrate her birthday.

Bass, Heidi Klum, Ciara, Jeremy Piven, Will.i.Am, Russell Simmons, actor Josh Lucas, "Lipstick Jungle's" Robert Buckley and Wade Robson were among Britney's guests at the club that was transformed with circus-themed accouterments, including a hot dog stand, cotton candy machines, a man on stilts and jugglers.

The birthday girl also had members from Team Brit by her side, including mom Lynne Spears, dad Jamie Spears, and manager Larry Rudolph -- along with her assistant, choreographer and reps from her label, Jive Records.