There is one fundamental difference between Rock School and School of Rock, and it is not that the former is a documentary whilst the latter is a feel-good comedy. Let’s break it down:
SCHOOL OF ROCK: Slightly overweight band loser teaches kids about the power of creativity and learning through fun by getting them to play rock music.
ROCK SCHOOL: Slightly overweight band loser teaches kids about the power of creativity and learning through fun by getting them to play rock music. Unfortunately this is just a distraction as the Slightly Overweight Man then enacts his revenge on the kids and the world: BY MAKING THEM PLAY FRANK ZAPPA SONGS! AND THEN MAKING THEM GO TO A FRANK ZAPPA FESTIVAL IN GERMANY AND PLAY MORE FRANK ZAPPA SONGS AND LISTEN TO FRANK ZAPPA UNTIL THEY JOIN THE ZAPPA LEGION OF THE DAMNED
One is a feel-good comedy. The other is clearly a horror movie.