Check out four unforgettable collaborations that took place during the FireAid benefit concert, including a Stephen Stills-Graham Nash reunion and a duet between Stevie Wonder and Sting.

When the first song of the night features record-smashing pop icon Billie Eilish out the front of pop-punk royalty Green Day, you know you're in for something special.

FireAid LA brought together a powerhouse lineup at the Kia Forum and Intuit Dome in Inglewood to support relief efforts for the devastating wildfires that have claimed 29 lives and caused billions in damage.

The event, set to take place on January 30, will also stream live on Apple TV, Netflix, Paramount, Prime Video, Spotify, SoundCloud and YouTube

They join Billie Eilish, Stevie Nicks, Joni Mitchel, Green Day, Red Hot Chili Peppers, Lady Gaga, Stephen Stills, and many more.

Two concerts collectively referred to as FireAid kicked off at the Kia Forum and the Intuit Dome in the Los Angeles city of Inglewood to support relief efforts in the wake of the deadly wildfires that ignited earlier this month in the LA area,

From surprise guests to touching moments of humility, here were the most memorable moments from the Jan. 30 FireAid benefit concerts in Los Angeles.

Music legend Stevie Nicks told a packed audience at Thursday’s FireAid benefit that Santa Rosa firefighters saved her Pacific Palisades home during the Los Angeles wildfires and dedicated a song to the group.

Grammy Awards will include a special Los Angeles tribute and performances by Billie Eilish, Shakira and others.

Pink, who always dials it up to 100, performed Janis Joplin's “Me and Bobby McGee” and Led Zeppelin's “Babe I'm Gonna Leave You.” While introducing John Mayer, she addresses the crowd: “Ladies and gentlemen, and every other gender which absolutely exists,” seemingly a reference to President Trump's “two gender” declaration.

Billie Joe Armstrong and Billie Eilish. Green Day got things started at the Kia Forum, where they surprised fans with Eilish to help them perform, "Last Night on Earth" from 2009's 21st Century Breakdown.