Whiplash is a two hander between Miles Teller's young but talented Jazz Drummer and his mentor/band leader played by J K Simmons. The film opens with Teller a student at Music College, auditioning for the competition winning band that could make his career. Simmons, it's perfectionist conductor, brings him, and the film goes on to chart their relationship as he pushes Teller harder and harder to be better and better. The film goes through a few narrative twists on the way to it's denoument, that I won't spoil, but its not always making the most predictable choice, driving an ambiguity about the characters that is the films major strength.
The performances are excellent. Simmons has the showier role; a ranting, fuming ogre of a man, snapping from perfect stillness to volcanic explosions of fury and expletives. He's electric to watch, totally dominating the space in the rehersal room, and yet capable of subtle depth and shade outside it. On the other hand, Teller's character slowly unfolds over the film, initially more sympathetic by design but, as the film goes on his own consuming drive and ambition starts to leech the likablity out of him. To balance these two assholes we get Teller's Dad (Paul Reiser) and girlfreind (Melissa Benoist) with warm, human performances; Benoist especially makes a lot of a comparatively small role which will hopefully stand her in good stead for the upcomming Supergirl.
The other great love that shines through the film is for the music itself. As well as providing it's own soundtrack, the film frequently lets the music play, with a love of Jazz at it's heart. It's important that you understand this, it seems to say, it's important you understand what drives these characters, the desire to be part of this great sound. It's especially comes through in the films grand finale, driven by a mix of the music and the (nearly dialogue free) performances.
Whiplash is at times a difficult, ambigious movie with characters you wouldn't want to share a drink with. But it's an outstanding film, from it's score, to it's snappy editing and light design, to the two performances at the heart of it. It's also smart and confident enough to let its central question - "is it better to burn, than to fade away?" as I heard somewhere once - hanging, for the audience to decide. Really one of the best films I've seen this year, and very much worth seeking out.