The purpose of this instrumental case study was to investigate band teacher agency in a high-stakes performance environment. Research questions were: (1) What experiences and professional relationships were most salient in the past (iterative), present (practical-evaluative), and future (projective) dimensions of band teacher agency in a high-stakes performance environment? and (2) How did high-stakes performance practices, mediated by teacher agency, shape music teaching and learning in school bands? I used Emirbayer and Mische’s chordal triad of agency and Priestley et al.’s ecological framework of teacher agency as theoretical frameworks, and I collected data in the forms of interviews, observations, and document review in 2019. Participants’ agency emerged from their interactions with music education organizations that perpetuated a high-stakes performance environment. Powerful structures (state associations) and individual agents (band teachers) sustained each other through norms and values derived from their contextual discourse. Findings indicated that visions for holistic music-making and greater diversity and inclusion in school music must include structural changes in professional organizations. For example, state associations could enact policies that incentivize teachers to exert agency to engage students in other forms of music learning in addition to performance preparation.

这个工具性案例研究的目的是调查高风险表演环境中的乐队教师代理。研究问题是：（1）在高风险的表演环境中，乐队教师代理的过去（迭代）、现在（实际评估）和未来（投射）维度中哪些经验和专业关系最为突出？(2) 以教师中介为中介的高风险表演实践如何影响学校乐队的音乐教学？我以 Emirbayer 和 Mische 的和弦三元组和 Priestley 等人的教师代理生态框架为理论框架，并在 2019 年以访谈、观察和文件审查的形式收集数据。参与者的机构来自他们与音乐教育组织的互动，这些组织使高风险的表演环境得以延续。强大的结构（国家协会）和个体代理人（乐队教师）通过从他们的语境话语中得出的规范和价值观相互支持。调查结果表明，对整体音乐制作以及学校音乐的更大多样性和包容性的愿景必须包括专业组织的结构变化。例如，州协会可以制定政策，激励教师发挥作用，让学生参与除表演准备之外的其他形式的音乐学习。强大的结构（国家协会）和个体代理人（乐队教师）通过从他们的语境话语中得出的规范和价值观相互支持。调查结果表明，对整体音乐制作以及学校音乐的更大多样性和包容性的愿景必须包括专业组织的结构变化。例如，州协会可以制定政策，激励教师发挥作用，让学生参与除表演准备之外的其他形式的音乐学习。强大的结构（国家协会）和个体代理人（乐队教师）通过从他们的语境话语中得出的规范和价值观相互支持。调查结果表明，对整体音乐制作以及学校音乐的更大多样性和包容性的愿景必须包括专业组织的结构变化。例如，州协会可以制定政策，激励教师发挥作用，让学生参与除表演准备之外的其他形式的音乐学习。