The purpose of this study was to examine the relationship between time spent in nonperformance and critical thinking activities in high school choral rehearsals. Eighteen rehearsal observations were collected from public school music programs. Observed rehearsal behaviors were coded into three categories of nonperformance activity: lower-order thinking, critical thinking, and nonspecific activity. Results indicated that the mean rehearsal time spent in all nonperformance activities was 53.89%, with 45.96% focused on lower-order thinking skills, 6.36% in critical thinking skills, and 1.57% in nonspecific activities, including off-task behavior and silence. A significant positive correlation was found between the amount of time spent in nonperformance activities and time spent engaged in critical thinking skills. No significant correlation was found between the level of ensemble in which students were enrolled and percentage of time spent in activities that required the use of critical thinking skills. Findings suggest that amount of time spent using critical thinking skills in high school choral rehearsals may be influenced by a variety of factors, including rehearsal techniques and learning objectives used by master teachers.