The activities of drum corps and high school marching band are similar in many ways, and yet drum corps is styled as the "major league" of the marching arts. What makes the learning environment different between drum corps and high school marching band? While drum corps has a denser rehearsal schedule, and involved an audition process where high school marching band does not, the biggest difference between the two activities lies in the instructional practices utilized. Drum corps does not have to adhere to state or national arts education standards, and so the instructors must create their own standards and forms of assessment for the students, which directly affects student motivation. This student motivation can be understood through the Self-Determination Theory pioneered by Deci & Ryan, in which the conditions of autonomy, competency, and relatedness must be supported for students to reach the highest levels of motivation. By interviewing the directors of the Academy Drum and Bugle Corps, and the Casa Grande Union High School marching band, and surveying students of each organization, a comparison can be made in the instructional practices of each organization and the subsequent effect on student motivation. Through the interviews with the directors, it was gathered that instructors in drum corps had more chances to work with the students one on one, and assess their personal growth in a subjective manner than the instructors in the high school marching band. This affected the way in which the drum corps instructors structured their rehearsals and set their goals. High school instructors were able to assess technical skill more often with graded assessments such as playing tests or scale checks, though this did not always take into account the students' personal growth or experience. From the anonymous surveys of the students of both organizations, a desire for relatedness was communicated from the high school students more than the drum corps students, and a greater lack of comfort with asking questions was displayed from the high school students. Interpreting these results with SDT, it could be said that these high school students were feeling less motivated than the drum corps students due to a lack of fulfillment in the areas of relatedness and competence. In the end, it would seem that the differentiated instruction that is possible in drum corps sets the activity apart from high school marching band, as the instructors are able to work with students on setting personal goals and may subjectively assess their growth within the activity. Self- and peer-evaluation in drum corps is also facilitated through video assignments in which other students may give comments to their peers, which builds the area of relatedness more within drum corps students than in high school students.