A phrase like action movie or mystery novel calls to mind a particular aesthetic and emotional experience, but terms like country, hip-hop, and punk do more. They evoke a kind of person—an incomplete stereotype, certainly, but one that’s instantly legible to anyone who’s even minimally engaged with popular culture. And they also conjure communities: a crowd clad in black T-shirts, combat boots, and studded bracelets at a metal show; in Birkenstocks and cardigans at a folk club. Metalheads and folkies, separated by a chasm, each bond over a love for their chosen music, even if they might now both be endangered species.