Armstrong has been a fan of Eilish since the beginning of her career.
Its like an earnest person thats expressing themselves and incorporating new sounds.
Some of it sounds like jazz to me, if thats cool to say?
Billie Eilish performs with Green Day during the FireAid benefit concert.Chris Pizzello/Invision/AP
Eilish left the stage after Last Night on Earth, and Armstrong addressed the audience.
Los Angeles, he roared.
We are still alive!
And were all in this together.
