As a kid, I actually watched the saturday morning cartoon version of this regularly.  I have no explanation for this.  Somehow, I was entertained.

The main difference between the live action version and the cartoon, apparently, is that the band no longer plays watered down sixties pop-rock, but instead plays watered-down punk.  Since this is a significant improvement in the amount of rockingness, the movie might actually be listenable.  Word of mouth seems surprisingly positive for this, given that it's just a shallow little inoffensive kids' film... I might have to actually watch this.