A structured rehearsal hierarchy involving a multiple-baseline design, implemented across six rehearsals, was used to measure performance improvement of seven musical concepts, while an experimental design nested within was used to examine the effect of teacher reinforcement on attentiveness, achievement, and attitude in choral ensembles. Two high school choirs (N = 60) received either task presentations, directions, student performance, and reinforcement (n = 31), or identical instruction with no verbal/facial reinforcement (n = 29). Forty choral performances were evaluated by three expert judges, with individual concepts evaluated using 10-point scales and overall performances evaluated using 100-point scales. Results indicated similar performance gains were made for all excerpts, though less instructional time was needed to teach previously learned concepts in new musical contexts. Performance gains made immediately after instruction were maintained despite the addition of new musical concepts. An 11-day period without instruction resulted in a slight ratings decline, but scores recovered to previous levels quickly. Students receiving feedback had higher performance ratings, recorded a more positive attitude toward rehearsal, and were observed off-task a larger percentage of instructional time than students receiving no feedback, with both groups demonstrating lowest off task percentages during group performance activities.