Relations between music education structures and teacher agency are under-researched and under-theorized, and scholars have indicated that the traditions and competitions of school bands in the U. S. may constrain educator agency. The need for research on teacher agency in competitive environments is compounded by policy trends toward administrators' use of festival scores in music educator evaluations. The purpose of this instrumental case study was to investigate band teacher agency in a highly competitive music education environment. I used the chordal triad of agency as the primary theoretical framework. Participants were four mid-career band educators in Texas, and I collected data through interviews, observations, journal entries, website review, and email correspondence. Throughout the data, participants' agency largely reproduced existing structures. Findings coalesced around (a) participants' core values of music, students' development, hard work, and competition, (b) an inductive, cohesive collection of band teaching norms despite participants' employment in schools of varying urbanicity and student demographics, (c) power sources that transmitted values and directed teachers' agency, and (d) a compelling story of one participant's generative agency that contrasted with the rest of the data. I provide directions for further research on music teacher agency and suggest implications for band educators, professional music education organizations, and music teacher educators.