Whiplash, Saturday, BBC Two, 11.20pm The dramatic possibilities of obsessions and obsessive behaviour are red meat for film-makers, particularly where the arts are concerned. Think Black Swan, The Red Shoes, maybe even Amadeus and Birdman, which deal with ballet, classical music and theatre acting respectively. Director Damien Chazelle hit critical paydirt in 2016 when, aged 32, he became the youngest winner of the Academy Award for Best Director for the musical La Land, featuring Ryan Gosling as a Los Angeles jazz pianist struggling to make a name and a career. But two years earlier he had announced himself with another jazz-themed film, Whiplash, and boy does this one feature obsessive behaviour. At its heart, a troubling and abusive teacher-pupil relationship.