the time of Auden's arrival at the GPO, Cavalcanti suggested to Grierson that he hire 22-year-old English composer Benjamin Britten to contribute music to the film department, including the musical score for Night Mail. Grierson accepted, assigning Britten a weekly salary of £5. Watt urged Britten to avoid "any bloody highbrow stuff", and showed him the picture while playing an American jazz record and requested "this kind of music". Britten had little interest in jazz music, but was given artistic freedom to compose. He was allowed an orchestra of ten musicians, and used a compressed air cylinder and sandpaper to create a "sound picture" of the pistons and pumps of a steam locomotive at speed. The music was recorded at the Blackheath studio, Jackson claimed Britten had only used five musicians, all of whom were hand picked. In order to keep the orchestra in time, Britten conducted to an "improvised visual metronome" that involved marks cut at particular intervals in the film that appeared as flashes on the screen. By 12 January 1936, the music had been written which was followed by the recording sessions that began on 15 January. Narration After the poem sequence was finalised, the remaining sound recording which included the narrative commentary. Wright thought Jackson's voice was suitable for the part and suggested it to him. Jackson agreed, but disliked the sound of his voice upon playback: "My dulcet tones are immortalised in a few simple statements [...] I sounded like some Oxford pimp on the prowl, and never having been to Oxford, I should know". Release The film premiered on 4 February 1936 at the Cambridge Arts Theatre in Cambridge as one of the films presented at the launch screening at the venue. A screening was held the following morning. Jackson, Watt, and Wright were among the GPO staff present; the former recalled the audience's enthusiastic response to the film which included an "enormous applause" at the end. The film was the GPO's only production to be released commercially in 1936. Wright was angered upon its general release as he found out that he was jointly credit as producer and director with Watt, when he believed he had done most of the work. Watt was shocked to find that he was credited as a producer, as he argued he had only directed the film. He tried to have the on-screen credits changed so his name