Understanding how students make music in non-school settings can inform teaching practice in schools, making teaching more relevant to students' musical perspectives. This research study examined the musical processes of a three-member rock band, their roles within the group, and considered how they constructed musical meaning. The most salient findings that emerged from this study lie at the intersection of musical growth, musical enculturation, and musical meaning. Collaborative composing was facilitated by shared musical tastes and grounded in friendship and commitment to music making. Engagement and investment in the music prompted meaningful musical experiences for group members. Ownership, agency, relevance, and personal expression fuse at the core of the value they place on this musical and social experience. Implications for the instrumental music classroom are also shared. (Contains 7 notes.)