Britney Spears Rocks New York Nightclub With Circus-Themed Birthday Party

Party is attended by Ciara, Lance Bass, Jeremy Piven, Britney's mom.

She's got a Circus theme for her album, her tour, her "Good Morning America" appearance and even her birthday party.

For her 27th birthday bash in New York on Tuesday night, [artist id="501686"]Britney Spears[/artist] turned nightclub Tenjune into a three-ring circus. Brit showed up in a low-cut Roberto Cavalli cocktail dress, with her hair done up loosely. The party was attended by her mom, Lynne, as well as celebrities like [artist id="1801883"]Ciara[/artist], Lance Bass and Jeremy Piven.

(Check out photos of Britney from inside the party.)

The party was featured jugglers, a man on stilts and carnival concessions like hot dogs and popcorn, according to UsMagazine.com. Outside, circus images were projected onto a screen.

Spears told "Entertainment Tonight" her simple birthday wish: "A million more wishes!"

"I've definitely known her for a long time and it's been amazing to see the career she's had," Lance Bass told "ET" outside the party. "It's going to be an amazing career for her. It's great when people do themes to their albums."

Fellow partygoer Ciara was also excited to spend Britney's big day with her, and was hesitant to label Circus a comeback record. "I was actually watching her interview the other day where she said she doesn't like the word 'comeback,' so I won't say that," she told ET. "But, I'm happy her album is coming out. She's taking us into her circus and I'm enjoying it."

"It's going to be great to see her," Bass added. "I'm so proud of her. I'm really happy. I don't think she went anywhere. I think the album is amazing. I'm already falling in love with it."

As she was presented with a circus-themed birthday cake, Barry Weiss, CEO and president of Jive Records, Brit's label, told the singer, "We are so proud and so happy to be a part of your life. Looking at your two boys today, it's an amazing experience."