Ken Russell’s name remains a byword for excess, and few who see The Devils, Tommy or Crimes of Passion are likely to argue. But his desire to shock audiences was only part of his repertoire, and the skills he developed as a film-maker for the BBC’s Omnibus documentary series are exemplified by this untypically retrained biopic of composer Gustav Mahler. Played in stern fashion by Robert Powell, Mahler’s life is explored in flashback structure, with emphasis on religion and family. There’s also a strong pictorial sense of landscape; Russell often complained about the lack of countryside in British films, with the Lake District making a picturesque background. Sure, there’s an Oliver Reed cameo and an anachronistic dream sequence featuring Nazis, but Russell keeps the bit between his teeth and delivers an austere, dignified picture of musical genius that, shorn of any of the sensationalism Russell was regularly criticised for, almost no-one saw in 1975.