alicia-keys_keep-a-chils-alive-black_ball_0710081NEW YORK — For Alicia Keys, one star-studded night could change the world. The singer played host Thursday night at the Hammerstein Ballroom at her sixth annual Black Ball, which benefits the AIDS organization Keep a Child Alive.

Change is a thematic reference in all of Keys’ recent projects. Her next album, due Dec. 1, is titled The Element of Freedom, and she recently set up AK Worldwide, a company to handle her philanthropic affairs.

But the Black Ball is “something I build up to for the entire year,” Keys said backstage before the festivities. “I’m in the middle of finishing my album because you know it comes out on World AIDS Day, which is very intentional for me.”

Event co-host Padma Lakshmi, in a long red Gucci dress, arrived boasting her own change — a pregnant belly.

“I look both ways before I cross the street now,” the Top Chef host said with a laugh. “I’m not a mommy yet. I’m a mommy-to-be so I’m learning all about it. I’m reading voraciously on the subject. It’s very early days.”

Fellow co-host Iman, a native of Somalia, wore a glittery Thakoon number. “We started off six years ago hosting this in a synagogue downtown. It’s amazing how far we’ve come. In the West, AIDS is not a death sentence. That’s what we’re striving for” in Africa and India.

Former president Bill Clinton was to be honored for his foundation’s work, alongside Sir Richard Branson and Senegalese singer Youssou N’Dour.

Other celebrities at the Black Ball: Nick Cannon, Mary J. Blige, Samuel L. Jackson, Adrian Grenier and Tyson Beckford. Model Gabriel Aubry accompanied partner Halle Berry, who wore a slinky black dress.

Jackson was there thanks to Keys’ mom, Terria Joseph, who “texted me weeks ago,” Jackson said. “We used to do theater together.” He added, “The more we do, the wider we can toss this net, the better we can be.”