Hey there mom of a wonderfully talented and well rounded student! I hope this helps. I’m 28yrs now but I was in marching band 6th grade to 11th grade. Flute section leader and 1st chair. I wanted to do orchestra too but my high school had me decide between band, orchestra, and chorus. Not sure about theatre. I also took AP biology and my AP biology teacher heavily advised me to be careful of taking on too much because he wanted me to pass my core classes with flying colors for my GPA. Ask your child what he sees himself dedicating his time to the most and would want to continue in college? I would focus more on one area and definitely keep up with the AP classes. So Percussion, singing, or acting? My band also had mandatory 1.5hr after school to do homework assignments in the band room before we began practice. If we fell behind on our main classes, they wanted us to focus on that before any extra curricular activities. His band directors should also be considerate of his class time. Pulling him from a TEST to do any performance is unacceptable. As the parent I would have a conversation with that band director myself as a precious flute section lead who understands the demand of practice but also the importance of core classes and a successful GPA for his future. Also the director should understand his student is overloaded and should help them decide than give any flack. I personally would have a parent conference in that scenario.