This business is very political. People talk and people have friends. I don't know your head director or you. But maybe your head director was a great director once upon a time. He may have had great bands in the past and now is burned out and is waiting to retire, which is wrong. Then again, maybe he was always a bad director, which begs the question, why did you take a job there? If your answer is, I needed a job and wasn't getting a lot of offers, there you go. Another reason you don't need to start burning bridges no matter how right you may be about the head director.
The administration may like this person. If you march in there with one year of experience and start running this guy down, you may find that you are the one who is ousted and looking for another job. And if that happens, you'll need them for a recommendation. How do you think that's going to work out?
In my opinion you need to do all the work that is thrown at you and do it very well. This is an opportunity for you to shine and grow. Since you are a first year teacher, you will gain a lot more experience at honing your skills by working your butt off and taking on the extra load.
Keep your mouth shut and leave at the end of the year. It will look better to leave a place with a recommendation that you were a team player and worked hard, than you were a whiner who backstabbed the head director. Yeah, yeah I know, it's not fair. If you stay in this profession for 30+ years like I have, you'll find a lot of stuff in our business that is not only not fair, but very corrupt.
Focus on the kids. Focus on improving your craft. Forget the other staff members. I've been in your shoes and I've also been a head director for many years in both small and large schools. Good luck whatever you decide to do.