With a celebrity-studded crowd looking on, rocked the halftime show at the NBA All-Star game on her 23rd birthday.

She had other big names helping her sing her hits Sunday, with joining in on “What’s My Name?” and working “happy birthday” into the lyrics. Dripping in gold chains, a red-clad came out for “All of the Lights,” which is off his latest album but features .

The red-haired singer soon shed her short black suit jacket and white scarf to reveal a short black skirt and a rhinestone halter. She shimmied her way through “Only Girl (In the World)” and didn’t flinch when her huge hoop earring fell off her left ear in mid-song.

Beyonce and hubby sat courtside, with (MVP of Friday’s All-Star celebrity game) two seats away. Sean “Diddy” Combs, (wearing headphones), Grammy winner , , , , and “American Idol” judge were scattered around the arena. Rapper snacked on pink cotton candy. Later, sat courtside next to 16-year-old Bieber, making for a striking contrast between her flaming long hair and his famous shaggy ‘do.

Among the movie and TV stars in attendance were Dustin Hoffman, Spike Lee, Warren Beatty, Rick Fox and girlfriend-actress Eliza Dushku, and Nick Cannon (without wife Mariah Carey). CNN talk show host Piers Morgan furiously worked his cell phone during most of the action.

Snoop Dogg, Terrell Owens, Chris Tucker, tennis star Venus Williams, and actors Forest Whitaker, Noah Wyle and Ellen Pompeo took in the show, too. Los Angeles Lakers fan Jack Nicholson was bumped out of his usual courtside seat.

While Howard and many of the other arriving NBA players dressed up in suits and ties, Lakers star Bryant dressed down in jeans and a black leather jacket. ap