Billie Eilish joined Paramore during their North American tour in Los Angeles.
During the show, they sang “All I Wanted.”
The video, going viral, shows fans in the crowd losing their minds when Billie comes on stage.
Williams and Eilish previously sang together during Coachella last year, and they sang “Misery Business.”
What other song would sound good if they teamed up and did a duet of it?