This study investigated whether and in what ways a learner-centered instrumental music education classroom environment may nurture musical growth and independence. The mixed-methods design incorporated quantitative and qualitative measures to compare performance outcomes, musical growth, and learner and teacher dispositions in learner-centered and teacher-centered middle school orchestra classrooms. Quantitative measures included a Performance Assessment Instrument and a researcher-designed survey of student perceptions and attitudes. Qualitative measures included classroom observation, student and teacher interviews, and teacher journal entries. Research participants were four teachers, two of whom taught using a teacher-centered approach, and two of whom were oriented to learner-centered classroom strategies through a professional development program taught by the researcher. The teachers implemented learner-centered or teacher-centered environments in four intact classrooms that included 155 student participants. Learner-centered methods were based on democratic (Dewey, 1938; Woodford, 2005) and constructivist (Vygotsky, 1978; Wiggins, 2001) principles as well as research and pedagogical literature detailing the characteristics of learner-centered classrooms (McCombs & Whisler, 1997; Schuh, 2004). These included peer tutoring and collaboration; student conducting, solicitation and incorporation of student input; and facilitation of student leadership. I found no differences in music performance outcomes between learner-centered and teacher-centered ensembles. However, learner-centered students exhibited increased musical growth and greater musical independence as compared with students in the teacher-centered environment, and indicated higher perceptions than teacher-centered students of choice and leadership opportunities in their classrooms. Learner-centered teachers reported increased engagement and leadership skills from their students. Results of this study indicate that music ensemble teachers can incorporate a learner-center classroom environment that engages students musically, promotes independence and leadership, and involves students in higher order thinking while attaining performance standards at or above those expected of middle-school orchestra students.