Other: In the scene were the kids come in the class for the first time and see Dewey with music instruments, keep an eye on Zack the guitar kid. Just before Dewey says "you", Zack looked directly at the camera.

Continuity: When Rosalie Mullins walks down the corridor approaching Dewey's classroom there are children doing artwork as she walks past, she even comments on the child saying "three at once that is very clever". After she listens in at the classroom door she continues walking down the corridor as we can see her on the CCTV footage the children have set up. In this shot, however, the children are no longer painting where they were before and appear to be through the doors Rosalie is about to walk through.

Continuity: At the title sequence, after Dewey's solo, and just before he stage-dives, the camera cuts from him, to the lead guitarist, then back to him. In the first shot of him, he is just putting down his guitar. In the shot of the lead guitarist, the neck of the guitar is visible as if he was still holding and playing it, but when it cuts back to Dewey, the guitar has been put down, and Dewey has his shirt off.

Continuity: As Dewey says "You hate teachers, is that what you're about?", the black bespectacled girl has her hand on the table, but in the next shot, her arms are crossed.

Continuity: As Zach is 'raising his goblet of rock', his hand gets a lot lower in a shot change.

Continuity: During the scene at lunch when Dewey is telling the teachers a story, we see that the teacher who is sitting at the end of the table near Dewey is pretty close to him, but after Dewey tells the "gym teacher joke" we get a view of the table and the teacher that was nearest Dewey is farther away than before.

Plot hole: How is it that Dewey can hear a light orchestra a floor below and a room across (assuming the bathrooms are in the same location on every floor, making Dewey not directly under the music room), but the class next door to Dewey's can't hear a yelling, guitar playing, drum-playing class through a wall (this was before the "roadies" soundproofed the room)?

Audio problem: When Dewey starts playing his guitar towards the end (when he was leaning back in his chair with his feet on his desk, then leaned forward and stood up on the desk) we hear the drums starting to play. In the first shot of the class, the drummer is not doing anything except sitting behind the set, and there's still a beat.

Continuity: When Dewey leaves the bathroom after hearing the kids playing in the music class his shirt is sticking out of his waist band then in the next shot while he's running up the stairs his shirt is stuck back in again.

Other: During the credits when the band is having class, Dewey starts singing, "Credits got to roll. Look at that name there. I do not know that guy." While he sings that he pretends to follow one of the rolling names with his finger. Only problem is he's going the wrong way. He's scrolling down, but the credits are scrolling up. (Though an explanation is offered on the commentary, this is still a mistake within the film.)