I may have you at a disadvantage. My review might give some perspective;
Looking for Charlie Parker.
Astonishing. Pitch perfect.
The extraordinary ability to communicate musical obsession but also the power and perfection of a musical form like jazz. To do this in a second art form is remarkable. Using the language of cinema to transmit the beauty of music is what stuns me about this film. It would be enough to embrace the technicalities of jazz but to compose an expression in film form is the directors gift and achievement.
Don't you hate jazz by the midpoint of the movie? If this what it takes to perform, then what use is it? Except the film contains two characters who don't question what it takes to reach for greatness in this artform. JK Simmons convinces as a teacher trying to coax mastery; possessing another attribute of the educator, the ability to recognise potential. He also smells the hunger for attainment in people.
There is a conventional way to tell this story. The Red Shoes is a beautiful film about obsession in performance but also in svengaliism. Whiplash is about halfway through, ready for its second act at about the point Moira Shearer disappears under a train. Whiplash is effortlessly the movie Black Swan stumbles around trying to be- into the mouth of madness; but losing the focus of its goal, just to tell the story of damaged goods and how trying to be great will crack you down the middle. Miles Teller's Andrew carries a sure knowledge of his own potential throughout the film. He may be mad because in his reality, he is already Buddy Rich. He just needs the push of a great teacher.
This is the movie that you could describe as JK Simmons gets really angry. However he isn't an angry man. That implies restless frustration and impatience. In the moments outside the music, Simmons gets to display a man at ease with himself. Like most things in this intelligent film it doesn't labour the point, but it certainly makes it. He says he hasn't found Charlie Parker but he tried. He isn't justifying his disgraceful methods, which are truly abusive; just saying he believes that the search was his vocation; his responsibility. A movie that can adequately communicate such a concept is great indeed.
There's a section here, where a member of the studio group plays out of tune. Fascinatingly, the guy in question doesn't know whether he is playing out of tune himself. He can be told he is, because he doesn't realise the truth. It is a typical example of "Whiplash" exploring some deeper ideas. In Andrew's case, he is a markedly younger man than the other musicians playing at his level; playing a complex instrument, integral to the rhythmic form of jazz being performed. He can be moulded and he expects to be guided. He can be told he is wrong even if he is right. Part of the lesson is that you need to know for yourself, and that is part of the package of talent. When Simmons says, "not quite my tempo" he means that Andrew might be right, he might be playing perfectly, but that might just be the first lesson; to become perfect, so that you can then endlessly change it up or down. That perfection in the context of the band is different from technical perfection.
Simmons teacher cannot assume the role of father figure because the role is successfully filled. Imagine the fireworks it would set off if it was Andrew's mother who had been left to look after him- it's an interesting decision not to leave the father gap for Simmons to settle into. So Simmons and Paul Reiser become...what? Symbols of compromise and no compromise? Nice and nasty? No spoilers but the actions of Simmons and Reiser in the final minutes, for me, emphasise that the director knows precisely what he is doing with these characters. {OH I CAN SPOIL! ANDREW GOES STRAIGHT FROM HIS DAD'S ARMS BACK OUT ONTO THE STAGE. I SAW THIS NOT AS A CHANCE TO GET BACK AT SIMMONS BUT MORE AS A REJECTION OF HIS FATHER'S ACCEPTANCE OF COMPROMISE. ANDREW DOES NOT WANT TO BE THIS MAN! IN DOING SO HE STEPS AWAY FROM REALITY FURTHER. AGAIN SEEING THIS AS AN INDICATION OF SUCCESS SEEMS BARMY TO ME. HE IS CREATING HIS OWN REALITY- SLIPPING FURTHER INTO MADNESS....GENIUS/MADNESS; IS THIS WHAT IT TAKES [NOBODY SAID CHARLIE PARKER WAS A NICE GUY DID THEY?]} I'm not saying I know what he is doing. I'm saying HE knows what he is doing, and I get to ponder what these men represent. How gorgeously chewy! I can masticate for days on this one small part of the meal that Damien Chazelle has set before me!
I will try to work out which genre this follows most closely. It isn't "A Star is Born". In fact, the physicality is akin to a sports movie. Perhaps it has that structure of dedication and life threatening bodily injury. Really I think it leaves genre behind very early on. The assurance of Teller's dinner table "I have no friends" is outside the norms. Travis Bickle levels of weirdness. Close to what Nightcrawler achieves with Louis Bloom. Quite a nihilistic worldview.
The film jarred my expectations. I love good music films. I don't care for jazz, in the sense that it doesn't draw me in the way other music does (it says nothing to me about my life- just to give away where my heart lies), but I wanted to be transported to a world of affection for it. The movie resolutely hates the music; makes it a trial and an academic study to be dissected and looked at through a microscope. However, finally it returns to the beauty of the form. It gives the music the final word. No more words no more anger. Just wait for your cue.
EDIT: I wrote "Pitch perfect" meaning to return to it. This isn't Pitch Perfect. Like I say I don't find it generic at all. From what you wrote, I think you do; so I think that's where the difference lies.