Global Citizen Festival: 5 Best Moments (So Far)

Beyonce performs onstage with Jay-Z at the 2014 Global Citizen Festival to end extreme poverty by 2030 at Central Park on September 27, 2014 in New York City

Pearl Jam, Beyonce, Coldplay & Ed Sheeran play 2015 festival Saturday in Central Park.

Music and activism collide once more Saturday at the Global Citizen Festival, taking place in New York's Central Park, with headliners Pearl Jam, Beyoncé, Ed Sheeran and Coldplay.

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The festival -- with its ambitious goal of ending global poverty by 2030 -- began in 2012, and over the past three festivals, a lot of superstars have joined forces onstage. Here's a look at five highlights from the past three fests:

Neil Young's Finale

In 2012, almost everyone on the lineup -- Foo Fighters, The Black KeysBand of Horses and K'Naan -- joined Neil Young & Crazy Horse to perform "Rockin' in the Free World."

Bey & Jay

There was that time in 2014 when Beyoncé joined Jay-Z onstage to sing Justin Timberlake's part on "Holy Grail."

Beyoncé, Coldplay, Pearl Jam to Headline New York's 2015 Global Citizen Festival

Stevie Wonder & Janelle Monae

Another legendary cameo came in 2013 when Stevie Wonder brought out Janelle Monae to sing "Higher Ground." Between the two singer-songwriters, the passion was palpable.

No Doubt & Sting

In a throwback to their 2003 Super Bowl performance, No Doubt and Sting teamed up yet again to perform "Message in a Bottle" at the festival in 2014. The main question from this performance: Will Sting or Gwen Stefani ever age?

Alicia Keys

The 2014 fest continued its reign of memorable moments with Alicia Keys' moving performance of "We Are Here," joined by Israeli musician Idan Raichel and Palestinian artist Ali amir-Kanoon.