“You would never know”: Billie Eilish Gushes With Zing the Art of Making Music to David Letterman Using Her ‘Happier Than Ever’

After hinting at a ton of amazing moments from the show, ‘My Next Guest Needs No Introduction with David Letterman’ is finally here and fans are going crazy over it. And as we get to know our favorite celebrities a little better with these episodes, so does the host, Letterman himself. In the…