Early in 2019, Dave Grohl raised eyebrows when he likened Billie Eilish’s connection with her (then rapidly growing) audience to what he’d experienced with Nirvana nearly 30 years ago. “My daughters are listening to Billie Eilish and they’re becoming themselves through her music,” he said. “What I’m seeing is the same revolution that happened to me at their age.” Since then—and the March release of her Apple Music Award-winning debut LP WHEN WE ALL FALL ASLEEP, WHERE DO WE GO?—Eilish has become the generational anti-star that Grohl had foreseen, a voice who speaks to and for young people in ways that feel essential to our current moment. In fact, not since “Smells Like Teen Spirit” has pop felt so organically alt and vice versa—thanks in large part to Eilish’s punk-like approach to inverting what we think we think about genres and their attendant aesthetics. It’s captured best by “bad guy,” a shape-shifting blend of nocturnal bass and hummable melody that’s at turns menacing and playful, with a delivery so close it feels like everything she sings and whispers was meant for you and you alone. That its official remix would feature a guest appearance by Justin Bieber speaks not just to its broad natural appeal but to her dizzying ascent as well: Teenage angst is timeless, no matter the form it takes.