Vaughan Williams composed the two duets, “The Last invocation” and “The Love-song of the Birds” for soprano, baritone, and violin with pianoforte (and string quartet ad lib.) in 1904. This study examines these two works, which were designed to be performed together, their origins, and the people and places associated with their premiere performances in Reading and London. It also discusses the biographies of the singing duo that premiered the work, Arthur Foxton Ferguson and Beatrice Spencer, and explores the Wagnerian influences in the music. Walt Whitman’s transcendental poetry, its appeal to Vaughan Williams, and the techniques by which the composer adapted and manipulated his chosen texts are discussed in detail. Through an examination of the various manuscript versions of the “The Love-song of the Birds” (all held in the British Library), the author proposes a chronology for the revisions of the work. Following its premiere performances, Vaughan Williams, and subsequently his wife Ursula after the composer’s death in 1958, suppressed Two Vocal Duets until 1996. This paper explores that suppression and argues why the materials, which were premiered in the same year as the song cycles The Songs of Travel and The House of Life, should now be published and made available to the public.