The purpose of this study was to examine effects of ensemble size and repertoire difficulty on listeners’ perceptions of concert band performances. Undergraduate music majors ( N = 210) viewed an audiovisual stimulus consisting of various images of large and small concert bands paired with identical audio performances of either an easy or difficult composition. Participants rated each ensemble’s tone quality/intonation, musicianship/expression, and rhythm/articulation using a 10-point Likert-type scale. Results indicated no main effects for ensemble size or order. There was a significant main effect for repertoire difficulty, with difficult repertoire being evaluated more positively than easier repertoire. We also found a significant Ensemble Size × Repertoire Difficulty × Order interaction, indicating that results were moderated based on order. Within the four orders, the largest mean difference in scores occurred in Order 3 (small/difficult, large/easy, small/easy, large/difficult), with the smallest mean differences occurring in Order 2 (large/difficult, small/easy, large/easy, small/difficult). The small/easy and large/easy videos and the small/difficult and large/difficult videos resulted in positive changes in ratings only when seen first and last, respectively. We recommend blind evaluation and the use of required “test pieces” in concert band festivals as ways to possibly mitigate effects of repertoire difficulty and ensemble size.