These letters see Britten in his prime; correspondents include librettists E. M. Forster (Billy Budd), and Myfanwy Piper (The Turn of the Screw), composer Francis Poulenc and the celebrated tenor Peter Pears, who was Britten's partner. Among friends in the US are Christopher Isherwood and Aaron Copland, and there is a significant meeting with Igor Stravinsky. This often startling and innovative period is vividly evoked by the comprehensive and scholarly annotations, which offer a wide range of fascinatingly detailed information. Donald Mitchell contributes an introduction exploring Benjamin Britten's creativity and an essay examining, for the first time, the complex relationship between the composer and the writer Edward Sackville-West.