But then Andrew turns the tables. He leads Fletcher's band into an incredible rendition of the song he was prepared to play. It's a powerful moment, despite the wringer the audience (and Andrew) has endured the whole movie. But there's also no question, as the audience watches its hero furiously bang out Fletcher's perfect tempo, that Andrew’s spirit is broken. Great art, or at least a great rendition, has been achieved, but at the total cost of the teen’s humanity. At the beginning of the film, he's obsessively driven and introverted, but relatably so; he works up the courage to talk to a girl he has a crush on, and kindles a brief if awkward relationship with her. He struggles with dinner party conversation. But as Fletcher begins to grind away at his confidence and sanity, Andrew withdraws further, breaking up with his girlfriend in robotic fashion and behaving more erratically until suffering a mini-nervous breakdown.
Fletcher is a terrifying, commanding figure throughout the film. Simmons is always clad in a tight black t-shirt that emphasizes his build; when we first see him conducting the studio band, he raises a hand in the air and the camera swings around him, as if at his beck and call. Director Chazelle often shoots Andrew as an isolated figure surrounded by negative space, emphasizing his enforced solitude, but Fletcher is far more dynamic. Simmons, doing some of the best work of his career, keeps you hanging onto Fletcher's every word even when you know his goal is to chisel away at Andrew's self-assurance. There's a scene later on in the film where he clearly explains his (predictable) modus operandi to Andrew: Fletcher believes great musicians can only be forged in a crucible of fear and torment, and says he’s just trying to get the best out of the best.
In an interview with The Dissolve, Chazelle says some of the inspiration for Fletcher came from his own high-school music instructor, and while he explicitly states that he himself doesn't share Fletcher’s mentality, he concedes, "I do believe in pushing yourself." Practicing music, he says, shouldn’t be fun, since you're supposed to be hammering away at your flaws. "If every single thing is enjoyable, then you’re not pushing yourself hard enough, is probably how I feel," he explains. "But this movie takes it to a extreme that I do not condone."
In the same interview, Chazelle says he thought Whiplash, especially its finale, followed the arc of a sports film. The comparison is apt: The hero is brought low and then surges back in the grand finale, winning a great victory at an undeniable physical cost.
That's perhaps where the problem lies for the movie’s critics. "We're supposed to leave our seats feeling just a little admiration for Fletcher and his alleged standards, because perversely, they really do tease out some greatness in Andrew," Stephanie Zacharek wrote in The Village Voice. "But Fletcher's tactics have nothing to do with talent, or greatness, or even just the complicated dynamics of playing music. He's just a cartoon bad guy masquerading as a complex one."