© The Author(s) 2012

Decades of research has identified a variety of positive effects of student involvement in extracurricular activities. We know little, however, about how these important positive benefits come about. This article examines the process involved in participation in high school marching band to show how students created strong connections through participation in the activity and developed interactional and affective commitment to the group that led to a high level of trust, acceptance, and self-confidence. Using both observation and in-depth interviews of members of the marching band at two Midwestern high schools—a rural school and a midsize city school—I found that members of each band developed a close-knit, socioeconomically diverse community. Within a marching band, students created a culture of trust and acceptance of individuality that provided a strong support group, which many students related to a feeling of family. The density of friendships in this activity strengthened students ’ identity with the group, thereby cre-ating a stable marching band identity for individuals. This study provides an explanation of the processes involved in developing the strong commitment to others in the group that led to marching band becoming a salient identity for many students