Selena Gomez, Olivia Wilde and More Fight Poverty at Global Citizen Festival

Jason Kempin/Getty Images

What do you get when you put Selena Gomez, the Foo Fighters and 60,000 people together in New York's Central Park? - The Global Citizen Festival.

Movie stars, rock stars and Victoria's Secret models put their fame to good use Saturday night for the largest syndicated live stream in history intended to raise awareness for eradicating extreme poverty. Millions watched it live streamed on YouTube, VEVO and several other outlets.

Festival co-founder 29-year-old Hugh Evans said the concert was purposely scheduled at the same time as the UN General Assembly in New York, so that they could get their message out to world leaders.

ABC News' Katie Couric, Olivia Wilde, Selena Gomez, Katherine McPhee came out to support various charities including UNICEF and Malaria No More and urge concertgoers to become "global citizens" by joining the movement. Beyonce and Hugh Jackman also joined in with video messages.

Neil Young with Crazy Horse, Foo Fighters and The Black Keys all volunteered their time to play at the concert which featured a surprise performance of John Lennon's "Imagine" by John Legend.

Rapper K'Naan also performed for free at the event and shared his story of growing up poor in Harlem and Toronto.

Fans looking for free tickets to the festival had to take action to support the poor. In order to register for tickets, they had to watch videos or read material about malaria, polio, women's rights and drinking water on

"I'm so excited about this idea," Evans told ABC News. "It turned the whole campaign around."

Tens of thousands of fans logged onto in the first few weeks.

Celebs at the festival also urged concertgoers to Tweet at President Obama and Mitt Romney, asking them to explain their plan to end extreme poverty worldwide.

Evans hopes the effort to fight poverty won't end just because the concert is over. He hopes to raise at least $500 million to help eradicate extreme poverty.