The purpose of this multiple case study was to investigate engagement in the collegiate concert band setting. Research questions were: (1) How do collegiate band students describe their engagement in large ensemble rehearsals? (2) How do collegiate band directors describe engagement in large ensemble rehearsals? and (3) What does rehearsal engagement look like in action? Cross-case analysis suggested that student engagement is related to personal/temporal factors, the repertoire and instructional strategies, and interpersonal factors among students and between the student and director. Directors spoke of the responsibility and pressure they felt to encourage independence and the challenges of establishing a collaborative, agentic environment. Observation field notes reflected variety in body language, liveliness, and hands-on interactions and technology distractions.