Factual error: At the "Battle of the Bands" scene, the kids arrive and have less than the length of one song to get ready to go on stage. (We see the band up on stage and hear the Battle of the Bands person tell the kids they're going on after that band.) Yet, when they get up on stage, they've got outfits, hair, makeup - including fancy braids and spikes - that just plain couldn't have been thrown together in five minutes.
Suggested correction: They're told they're on next, but it isn't known how long the gap is from one band finishing and the next one starting. The previous band can be heard playing as the parents are buying tickets. Then there's a cut showing the parents in the audience whilst no music is playing. We don't see the previous band leave, or the School of Rock go on. So it's possible there was a gap between the bands long enough for the costume change.
Factual error: When Dewey is getting the class to jam on "Smoke on the Water" for the first time, he tells the girl bass player to play a G, but he shows the guitar player the chords to the song in the key of A. The chords do not match the bass line. A real guitar player who has played this song would not make this mistake.
