Down and out rock star Dewey Finn (Black) gets fired from his band and he faces a mountain of debts and depression. He takes a job as a 4th grade substitute teacher at an uptight private school where his attitude and hijinx have a powerful effect on his students. He also meets Zack a 10-year-old guitar prodigy who could help Dewey win a "battle of the bands" competition which would solve his financial problems and put him back in the spotlight.