What is the fastest way to get ratted hair untangled?

I am putting on a performance tomorrow all day at school, and my hair is going to be teased and ratted. Well, my mom surprised me with tickets to Wicked for tomorrow night and we are leaving 30 minutes after I get out of school. I obviously don't want to wear my hair like that for Wicked, so what is a FAST, effective way to untangle hair?