Night Mail (1938)

The 1936 GPO Film Unit documentary about the overnight postal train from London to Scotland, and the most famous meeting of poem and picture in British film. W. H. Auden wrote the closing verse commentary and went through draft after draft with Harry Watt to match the rhythm of the moving train, while Benjamin Britten's score keeps time beneath it. Most of the film is a plain portrait of the train and its sorting carriages; the payoff is the closing stretch, when Auden's lines start to rattle along with the wheels. A free copy sits in the Internet Archive, and it is the best case for poetry as something you hear in motion.