This study examines the extent to which the perceptions of observers instructed to rate the quality of students' performances within ensemble rehearsals and applied lessons differ from those not so instructed. Music education majors (N = 52) wrote statements of observation during their viewing of a stimulus tape. All participants were informed of the instructional goals. Half of the participants (n = 26) rated the quality of student performance observed, while half did not. Participants' statements were classified according to topic, depth, and evaluative quality. Across both conditions, participants wrote more statements about teachers than about students. (Contains 2 tables.)