It is indeed, as a poster claims, a “groove,” a “duel” and a “revelation” and certainly one of the best movies I saw from 2014. “Whiplash” is a tense and surprising “overcoming obstacles” story that provides enough twists to keep you eager for more. The world of jazz students in their 20s attending a demanding academy feels claustrophobic; there is little else to occupy the story. But it is this focus and intimacy in the film that makes it work so well. I love it when storytellers know when to stop…