Thanks for that correction. I should have known better, having written a small thesis on Auden in another lifetime & knowing his voice! Yet his contribution to the film was more than just a poem; cf. Marsha Bryant, "Auden and Documentary in the 1930s" (1997) and www.theguardian.com/books/2007/d....

Stamp of excellence

Night Mail, about the London to Glasgow postal train, is a classic of the 1930s British documentary boom, with contributions from Auden and Britten. Blake Morrison marvels at its poetry and populism