After getting hundreds of pledges to tackle the world's problems at his philanthropic summit this past week, former President Bill Clinton did what any good host would: He threw a party.

Music, celebrity and politics mixed Saturday night at Harlem's Apollo Theatre, where Clinton was joined by Bono, Chris Rock, Shakira and Alicia Keyes for a roundtable discussion on youth activism.

Clinton called on each young member of the audience to "be a citizen servant, a giver, because we have to have a vital society," before announcing the Clinton Global Initiative's first youth summit, called CGI U, planned for next year at Tulane University in New Orleans.

Like the three-day Clinton Global Initiative philanthropic summit this week, the college version aims to bring together attendees to tackle global issues like sustainable development and poverty.

"What we are trying to do is make activism cool again for kids," Rock said.

The former president and the other superstar panelists took questions from the audience before giving up the stage to performances by hip-hop artist Wyclef Jean and soulful singer Keyes.

Clinton got some laughs from the crowd when he told them he was fulfilling a lifelong ambition.

"You know, I grew up playing music, and all my life I've wanted to play the Apollo," he said.

At this week's event, participants including heads of state, celebrities and business executives made 245 pledges on efforts such as treating neglected tropical diseases, protecting forests and enabling children to go to school for the first time.

Many of the celebrities on hand Saturday night had already made promises this past week at the summit.

Shakira said she would commit $40 million to help Peru and Nicaragua through ALAS, a coalition of artists and intellectuals committed to social change in Latin America.

MTV, which is partnering with the Clinton initiative on the youth activism summit, was to broadcast Saturday's event on several of its networks and online at its recently launched Think.MTV.com Web site.