‘He's one of the nicest people I know, but frightfully reticent,’ Britten wrote in his diary after a night of playing and singing his songs with Pears in October 1937. Already acquainted, they got to know each other properly following the death in April of mutual friend Peter Burra, who had been killed in a plane crash. On 6 May they had travelled together to Burra's cottage in Berkshire to help sort through some of his possessions. Although they were each involved with their own social circles at this point, they gradually built a friendship through shared interests: going to concerts and films, dinner and weekend parties, playing tennis and impromptu late-night song recitals. Their earliest letters show that music was central to the growing connection between them. In August 1937 Pears reports on the first concert performance at Salzburg of the Variations on a Theme of Frank Bridge, which Britten had completed the previous month. He offers his impression of the Boyd Neel Orchestra's interpretation and suggests how the performance might be strengthened. These first letters also demonstrate how each encourages the other in their respective professions, with Pears reassuring Britten that his work is the best in the programme and Britten promising to compose more songs for Pears to sing.

In March 1938 they rented a flat together in London at 43 Nevern Square, SW5, after the marriage in January of Britten's sister Beth, with whom he had shared lodgings since the early 1930s. Britten was now also the owner of the Old Mill, in Snape, near the Suffolk coast, which from April he shared with fellow composer Lennox Berkeley. Although he and Pears had clearly become close and enjoyed one another's company, their lives remained separate, as did their careers. Between late 1937 and March 1939, Britten supported himself by composing incidental music for the BBC and for the stage. He worked for the Group Theatre who produced plays by young, left-leaning writers like W.H. Auden and Christopher Isherwood, with whom Britten found much common ground, personally and politically.