In addition to many of the things already mentioned, very little of selecting the leadership team should involve the audition process. By the end of marching season, you should be able to pick your leaders for next year. I have 90% confidence that I could post a list in December and have only 1 or 2 students/parents with concerns.

We do interest meetings, interviews, teaching modules, conducting auditions, etc., but that's merely to legitimize the posted results instead of actually helping us decide who will be a leader.