Just as FireAid hit the five-hour mark, Billie Eilish and her brother Finneas turned down the volume for an acoustic set as the night neared its end. Eilish had already made a cameo to set off the event earlier in the evening,

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.