Some would say Whiplash is about a music conservatory student drummer who - with the help of a sadistic teacher - achieves success. But really the film is about a student who has to endure the abuse and manipulative tactics from the teacher on the way to achieving success.
The teacher - played brilliantly by J.K. Simmons - tells a story to the kid about how Jo Jones threw a cymbal at Charlie Parker's head and it made Parker practice harder until he achieved his legendary success. The story is apocryphal but it sets the stage for the lesson the teacher wants the student [Miles Teller] to understand, which is that abuse and intimidation will bring out the best in someone with talent.
I don't think the filmmaker - Damien Chazelle, believes this method works. But he teases it out enough to make us at least believe the student thinks it has some merit. However, by the end, he finds that the only real way to achieve success with this teacher is to fight back - and hard.
It's a terrific film; entertaining, intense and rather unpredictable. Especially the final scene when the student gets humiliated and then turns the tables - all on stage for the world to see. He finally finds a way to achieve the success he would have achieved earlier with a better teacher. But sometimes you have to overcome hurdles to win.