The lights dimmed at the Kia Forum, Green Day began to sing, and as a large screen showing photographs of burned homes flashed in the background, Billie Eilish stepped onstage to sing with them.

“Los Angeles, we are still alive!” said Billie Joe Armstrong, the singer and guitarist for Green Day. “This is California and we are all in this together.”

And with that, FireAid, the star-studded benefit to raise money for relief efforts after the devastating wildfires in the Los Angeles area was off and running. The two Billies were among the first of more than two dozen rock and pop stars who had all come to Inglewood, Calif., to do their part.

Billy Crystal, who lost his Pacific Palisades home in the fire, stepped onstage in the same sweatshirt and beanie that he had fled his home in. He told jokes, noting that the benefit had a simple goal: “to raise more money than the Dodgers spent on free agents.” But he grew serious as well, describing the searing grief of losing his home.

“From Altadena, to Malibu, to the Pacific Palisades, let’s show the world who we are,” he said. “We’re Los Angeles, one city, one heart!”

Then Crystal introduced Alanis Morissette, part of a lineup was so extensive that the concert was being held in two separate arenas. About 40 minutes into the concert, Dr. Dre was onstage calling out “the city of L.A.” in a rendition of Tupac Shakur’s “California Love” while Sheila E. played drums.