The purpose of this grounded theory study was to describe the process of adolescent choral singers' social identity development within three midsized, midwestern high school mixed choirs. Forty-nine interviews were conducted with 36 different participants. Secondary data sources included memoing, observations, and interviews with the choir teachers. The data analysis revealed an eight-stage process beginning with the student's choice to audition and remain involved to the final stage, a desire to give back to the community. The central phenomenon of social identity was identified as team. Contextual conditions, including time, intensity, and size of group, strengthened participant experiences substantively. Social cliques and egos emerged as intervening conditions that impeded social identity development. Several individuals influenced participant social identity including peers, parents, school and community members, as well as the choir teacher. A temporal matrix is presented as well as propositions illustrating the development of social identity.