What a wooden film. As a viewer, you cannot really get to know any of these characters. Nothing great comes from an abusive teacher. Hitting student in the face, really? No. It was unclear what JK Simmons' character really was after. Was it perfection? Is the only way to achieve perfection by humiliating students with verbal and physical abuse? The drumming was excellent. I'm a musician and I've never heard of students bleeding all over their drums. It's ridiculous. The only thing JK Simmons' character cared about was tempo. Talk about unidimensional. He crucified students only if they couldn't determine his tempo after a few beats. What about dynamics? What about interacting with the band? The script was superficial and lacking. People probably like this film because Simmons was an interesting character and the drumming was interesting. You'd think such a brilliant teacher would be a more impressive jazz pianist - another boring scene.