How to get my dad to let me go to ECC lessons?!

ECC stands for Extended Core Curriculum for those who don't know it is (it is sped lessons). I have Asperger's Syndrome and I hate music lessons. I get so stressed out by them and my friend who is also an Aspie says I will benefit a lot from ECC. My dad won't let me get help because "he doesn't want me audited by the school" but I can't take much more of this music (It is more than just not liking the subject - I hate the teacher too and I can't change easily because I am not in the SEP). None of the teachers know anything about my Asperger's (except a couple that know I have to wear earplugs in class) and it makes some things really difficult. When I have a meltdown it is really bad because I can't go to the SEP (or anywhere), and the teachers just think I am a really emotional teenager with bad anger management problems and they follow me when I need some space and report me to the office and stuff and it makes everything worse.

I think a whole heap of my problems would go away if my parents let me go to ECC lessons instead of music, that would mean that I have a little asterisk next to my name on the roll which means even supply teachers know I am in the SEP when I have a meltdown and that I learn important social skills that I lack and I can relax for that lesson because I am really stressed at school.

How do I convince him? I have already used the "my friend (who is very close in severity of our ASD) has benefited heaps from this and I think I would too."