That really sucks!!! And that's why I hated high school...sounds like little has changed regarding ganging up on people and bullying.
I'd have a face to face with that choir director who is clueless!! Kids have been know to commit suicide because of being bullied. (never your gal but it happens.) give him this link...
http://www.schoolsafety.us/pubfiles/...act_sheets.pdf
Really ticks me off!!