Meet Dewey Finn. He used to be a part of the really cool band. But after a while, he got kicked out. At that point, he had found himself in debts and with no cash. So, he stayed over at his friends place for a while. As that friend of his, Ned, lives with his girlfriend, it all becomes really inconvenient and complicated. Since Ned is also a former rock musician, Dewey tries to talk him into getting back into that world again and fails. At one point, Dewey answers the phone call about needing a sub teacher for a high elite school, and takes it, pretending to be Ned. His appearance in the school causes no suspicion and he forms a band out of talented kids in the class. He teaches them everything they need to know about rock music and history of it, so they are more than prepared for the battle of the bands, as it comes. There is only one thing that Dewey must take care of before he takes them to the concert- nice looking but pretty strict principal Rosalie Mullins (Joan Cusack), who runs that high elite school. If you like musicals combined with a good laugh, this is the movie you should really get your hands on.