Lil' D's heart is broken and his faith is shaken when his musical idol, Sunny Bridges, and his music teacher both go missing on the same day. Joined by his music fellow student music prodigies, Lil' D decides to have a benefit concert to raise money for a new music teacher, but is unable to sell tickets. Lil' D runs into Sunny, who has quit the music business and returned to Atlanta to lay low.

Lil'D and his incredulous classmates set out to convince Sunny to play at their benefit concert. Sunny rejects this proposition, but when he hears the kids play, he realizes that though he may want out of the music business, he doesn't want out of the music. He helps the kids with their concert and then agrees to become their music teacher.

Sunny's first lesson teaches the kids to be musically and artistically free. When Principal Luna gives Sunny an overwhelming number of teacherly duties, including being responsible for the annual Peanut Pageant, Sunny instructs his students to use their newfound "artistic freedom" to do a production that's so free that it's a free-for-all.

Intent on getting into the upperclass performance of "The Kong and I", Lil' D meets and befriends another drum prodigy- who happens to be a four hundred pound gorilla. The gorilla breaks out of the zoo to be with Lil' D, who soon finds that he is welcome in the play only if he can convince his reluctant ape friend to perform the title role.

The Westley kids stumble upon Sunny's old school yearbook and mistake his years in a funk band for a tour of duty as a pirate. They find a treasure map that leads to a cave where they awaken and unleash a toxic Sloppy Joe blob. Sunny himself has a connection to the blob and he and the kids must work together to save the day.