Damien Chazelle braced himself for disaster.
It was opening night at the 2014 Sundance Film Festival, and Chazelle's movie "Whiplash" was about to have its premiere in front of a packed house in Park City, Utah. Just six years out of college, Chazelle had written the film — a blistering tale of a young drummer (Miles Teller) under the tutelage of a cruel, manipulative music teacher (J.K. Simmons) — in a sort of fever of frustration after a string of earlier aborted scripts had gone nowhere.
Now, here he was at Sundance with all eyes on him, his stomach in knots, his heart doing paradiddles.
Chazelle — whose only previous directorial effort, a gritty,...