J.K. Simmons in ''Whiplash''

By Jeff Labrecque
Updated December 05, 2014 at 05:00 AM EST

Music professor Terence Fletcher wields tough love like a shiv. His mission: to forge greatness by applying physical and psychological pressure to his students, especially precocious drummer Andrew (Miles Teller). Fletcher’s rants leave marks on them and us. After all, wasn’t he the sweet dad from Juno? Simmons has built a career playing memorable supporting characters, including Schillinger, a sadistic inmate on the HBO prison drama Oz. ”When I first met J.K.,” says Whiplash writer-director Damien Chazelle, ”I told him, ‘Remember how you were in Oz? I want to make that guy look like the teacher in Mr. Holland’s Opus.”’ Simmons, 59, sympathized with Fletcher’s quest for excellence, but not his brutal methods. ”In my experience, that can be antithetical to creating artistic genius,” he says. That doesn’t mean he didn’t have fun, though. ”Smacking Miles around was a joyous day on the set.”