Staging a giant concert to generate social change seems like an idea straight out of the 1960s. Yet for the last two Septembers, the Global Citizen Festival has taken over Central Park and driven a total of more than 250,000 people to take 1.6 million actions -- ranging from signing petitions to emailing world leaders -- aimed at fighting poverty worldwide. Each action earns people points that can be used to enter a drawing for free tickets. The next drawing is Sept. 10. For info, go to globalcitizen.org/festival.

This year's concert will be headlined by Jay Z, but there will be plenty of other star power onstage. Here's a look at what to expect.

 

No Doubt

THE SKINNY: After Gwen Stefani's career as a solo artist took off, it seemed that No Doubt were done. Then in 2012, the band released its first album in more than a decade and it has dropped hints that more new music is in the works.

DID YOU KNOW? Stefani was No Doubt's third choice as lead singer.

 

Carrie Underwood

THE SKINNY: As one of the most successful women in the history of country music, Underwood rarely opens for anyone. After wrapping up a worldwide arena tour and appearing in NBC's live version of "The Sound of Music," she is in the early stages of working on a new album.

DID YOU KNOW? During Season 4 of "American Idol," Simon Cowell accurately predicted that Underwood would become "Idol's" best-selling winner.

 

fun.

THE SKINNY: fun. is still working on the follow-up to its breakthrough 2012 album "Some Nights," which gave the world the inescapable single "We Are Young." The anthemic indie-pop trio premiered a new song called "Harsh Lights" in a surprise appearance on "The Tonight Show with Jimmy Fallon" in June.

DID YOU KNOW? "We Are Young" marked the first time a rock band hit No. 1 on the Billboard Hot 100 with its first chart entry since Nickelback did it in 2001.

 

The Roots

THE SKINNY: Anyone who has seen The Roots in its role as house band on "The Tonight Show" knows the band can play just about any style of music. The group's live show proves it, moving from blazing hip-hop to soul to covers of Led Zeppelin and Guns N' Roses.

DID YOU KNOW? In addition to being a musician and author, Roots leader ?uestlove was briefly a restaurateur. His Chelsea fried chicken restaurant Hybrid closed last year despite good reviews.

 

Tiesto

THE SKINNY: In the early 2000s, Tiesto was one of the first DJs to go mainstream, laying the groundwork for the breakthrough of EDM over the last few years. His latest album is an upbeat crowd pleaser that he says was heavily influenced by Las Vegas.

DID YOU KNOW? Tiesto was the first DJ to perform solo in a stadium. He also was the first DJ to play live at an Olympics, taking the stage at the 2004 summer games in Athens.

 

If you go: Global Citizen Festival is Saturday, Sept. 27 at 3 p.m. at the Central Park Great Lawn.