Big Sean at the 2017 BET Awards at Microsoft Square on June 25, 2017 in Los Angeles, California.

Big Sean at the 2017 BET Awards at Microsoft Square on June 25, 2017 in Los Angeles, California.

*Stevie Wonder, Green Day, The Lumineers, The Killers, and The Chainsmokers are set to headline the Sept. 23 Global Citizen Festival, the annual concert in Central Park that promotes social activism.

The event, now in its sixth year, will also feature performances by Pharrell Williams, Big Sean, Andra Day, and Alessia Cara, organizers announced Tuesday. The lineup is curated by Coldplay’s Chris Martin.

Wonder returns for a second time as headliner following his marquee slot in 2013. Pharrell sang at Global Citizen’s offshoot festival in Hamburg, Germany, last month, which was timed to coincide with the G-20 summit of world leaders.

Hugh Evans, the CEO and founder of Global Citizen, tells Variety: “We try to bring in artists from multiple genres. We don’t want to just hit the rock demographic or just hit the pop demographic or just hit the R&B demographic or just hit the EDM demographic. Whatever music you’re into, you can come to the Global Citizen Festival and be part of it, because ultimately our hope is that the message transcends the music, that we’re the generation that sees the end of poverty in our lifetime.”

As in the past, 60,000 tickets are expected to be given out for the festival, essentially as rewards to participants in Global Citizen’s initiatives to end extreme poverty worldwide and tackle other social ills.

By signing petitions or tweeting messages at world leaders urging them to take action on issues such as girls’ education and sanitation, participants – mostly millennials – become eligible to enter a lottery for tickets, which are free.

Last year’s festival, which featured Rihanna, Metallica, and Usher among others, took place in the middle of the U.S. presidential campaign. Since Donald Trump’s election, Evans said, the need for action has become even more urgent – especially in light of Trump’s call to slash billions of dollars in foreign aid from the U.S. budget – and the level of engagement among Global Citizen’s followers has skyrocketed.