Billie Eilish and Finneas, Olivia Rodrigo, Earth, Wind & Fire, Gracie Abrams, Green Day, Jelly Roll, Joni Mitchell, Katy Perry, Lady Gaga, Lil Baby, Pink, Red Hot Chili Peppers, Rod Stewart, Sting, Stevie Nicks and Tate McRae are among those performing at the dueling shows at L.

"From the bottom of our hearts, we love you Los Angeles," Billie Joe Armstrong told the crowd, "and we've got your back no matter what"

Billie Eilish made a surprise appearance on stage with Green Day on Thursday to kick off one of two star-studded concerts in Los Angeles put together to raise funds for people affected by deadly wildfires in California this month.