Like the idea of the teenager, the definition of “teen pop” is always changing—just ask now-grown bobby-soxers, Beatlemaniacs, and Backstreet fans. But at its core, it’s always been synonymous with hooky songs that chronicled heartbreak, soundtracked dance crazes, and let adolescents blow off steam. The 2020s’ embrace of video-sharing sites accelerated the pace of teen pop’s evolution, with pop-punk and emo-rap just two of the styles that dominated trending charts. But the emotions expressed in song by the likes of Olivia Rodrigo, Billie Eilish, and Tate McRae are timeless.