The purpose of this multiple case study was to examine the impact of teacher transition on established secondary school music programs. Through semi-structured interviews, I explored outcomes of teacher transition through the lens of the Social Identity Theory. The sample consisted of: (1) a large Southeastern Florida suburban music program where the music teacher transitioned following a tragic incident in the school; (2) a medium Northeastern Ohio suburban thriving vocal program that transitioned to a new director in the last two years; and (3) a large, private Northeastern Ohio School located in an urban school district where a former music educator is now the principal responsible for hiring the new educator. The participants included teachers, students, parents, and administrators who have been involved in transitions of the leadership of established music programs. Three research questions guided this multiple case study: How do music teachers who have taken over leadership of established programs describe their experience related to the facets of transition? How do non-teacher participants involved in established music programs describe their experience related to the facets of transitions? How are the elements of group identity impacted by teacher transition? Data collection consisted of individual interviews, email correspondences, program handbooks, and researcher journal notes. Results suggested that the transition process ended when every student who had the predecessor graduated. Any changes to the program caused threats to the group identity resulting in negative behaviors towards the incoming teacher. The predecessors? acceptance of the new teacher did not impact the transition process, and students were impacted by how they were told their predecessor was leaving and their involvement in the hiring process. Students were motivated to continue in the ensemble if the predecessor encouraged them to do so and if the program achieved the high standards that the members of the group expected. The findings of this study may assist teachers who are choosing to leave their current program, administrators who are tasked with filling a position, incoming teachers to a new program, students, and music booster organizations to understand and help navigate the transition process. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]