It's All Happening argues that musicals about high school of the 2010s (Heathers, Bring it On, Jagged Little Pill, The Prom, Mean Girls, Be More Chill, and Dear Evan Hansen) collectively frame the high school experience as a kind of performance-both through narratives that often foreground the performing arts, and also by reveling in the ways adolescents navigate this challenging time by consciously performing versions of the self. By elevating an often-maligned adolescent genre, this book takes seriously the subversive potential of musicals set in high school to challenge oppressive systems, highlighting the ways in which these musicals wed fun with a commitment to social critique. 2010s musicals about high school signal social progress and complex new attitudes regarding teenage identity, responding to changing cultural understandings about adolescence, community, and inclusion. The conflicts of these stories treat high school experiences with care and thoughtfulness, enabling younger audiences to feel seen. Chapters focus on social hierarchies, queer and trans politics, digital technologies, intergenerational collaboration, and affect. In addition to historical and theoretical analyses of 2010s high school musicals, this book also features ethnographic research of high school theatre programs producing these musicals, asking what it means for students to perform characters their own age, going through similar life experiences.