Last time I was in the classroom, I had 6 classes, before and after school hall duty, and lunch detention supervising. Depending on what we were doing, that was 3 or 4 preps. I also had a last hour plan period, so no bathroom breaks for six hours. The "regular" teachers had 5 classes with the same prep, a plan and a PLC plan period. When the kids were on a field trip, we manned the denial room for the kids whose behavior etc. kept them off the trip. Music is an unbelievable amount of outside work with so many things that no one without extensive music training would understand. I'm also going to point out something else since your argument is that it's unfair. To quote my SPED prof., "Fair doesn't mean everyone always gets the same; fair means everyone gets what they need." You're a sub there, so it's not your problem or place to criticize. If the teachers at the school have a problem with it, it doesn't affect you. Trust that the schedule is the way it is for a reason. Even if you didn't intend it, your words come off as accusatory, which is something for which specials teachers have little patience. Being regularly undermined by "regular" teachers and admins makes the general suckiness of teaching worse and we get defensive quickly.