The purpose of this study was to determine the convergent validity of self-reported and objective measures of school music ensemble participation. Self-reported survey responses to a question about high school music ensemble participation and administrative data in the form of high school transcript-indicated ensemble enrollments were compared across N = 62,110 observations. Cohen's kappa (?) showed substantial agreement between self-reports and the administrative data. Evidence from the study suggests that self-reports are a valid measure of music ensemble participation, suitable for use in social scientific music education research.