Being a music student and a drummer, this movie was pretty ugly to watch. In a way, teachers need to be more like him, they need to push their students harder than they do. The hard part about teaching is probably to know when to stop pushing and instead ask if something's wrong, and be on the nicer side. The fact that the dude in the movie didn't have a nice side at all is what made him feel like satan in human form. Had a teacher a bit like him before, but had a nice side and wasn't too extreme, and he was probably the best teacher I had.
Whiplash.
Contrary to what people tell you, it's not a movie about a music teacher who screams at his students, but actually, a movie about what success, sacrifice, and hard work means. The best way to sum it up is "If you fall downget punched to the floor rek yerself seven times, stand uppunch back un-rek yourself eight times."