Sustaining and increasing participation in secondary music classes has been a regular topic of discourse within the field of music education. Music researchers and professionals have recently addressed specific issues related to music participation such as access to music classes, policy initiatives, and student interest in the music curriculum. This review of literature is an exploration of student enrollment trends in secondary music classes and a broad examination of the many factors that influence student enrollment decisions. In this review of literature, I frame music participation as a complex issue where multiple factors influence enrollment in secondary music classes. Next, research on the structural, interpersonal, and intrapersonal factors that affect music participation are presented. Finally, I address how music teachers and advocacy leaders might direct their efforts to support and increase music participation.