Timcop’s review published on Letterboxd:
Like the bastard child of all the 80's feel-good John Hughes movies, Pump Up The Volume takes a lot of the same tropes from those films and turns them on their head. Unlike those Hughes films, the adults in this film are almost pure evil, with the student body being called to action by the cause celebre created by a fly-by-night pirate radio dj who happens to be a member of that student body.
Mixing a punk attitude, 80's indie rock, and an X-rated sense of humor, Christian Slater somehow makes a completely watchable movie that mostly consists of just him talking by himself. Probably a little less than an hour of the film's total running time consists of Christian Slater ranting into a microphone, which sounds terrible on paper, but his performance completely sells it in this one. Also just as convincing is his "mild-mannered student" act that he plays in front of his classmates and parents.
Minus half-a-star because they never explain where those students got that giant inflatable penis.