Michael Tippett called T.S. Eliot his ‘spiritual and artistic mentor’, but the relationship between the two men has never been studied in detail. Eliot's numerous discussions with Tippett in the 1930s proved a lasting influence on the composer's beliefs about the coming-together of words and music. This article has three aims: first, to use Tippett's correspondence and writings to bring together the most accurate and complete biographical description of the relationship to date; second, to show that Tippett quoted from and alluded to the work of T.S. Eliot not only in his early pieces (as has hitherto been thought) but in much later compositions such as The Ice Break, The Mask of Time, and Byzantium; and third, to examine the libretto of Tippett's oratorio A Child of Our Time in the light of the composer's talks with Eliot. This article suggests that the inclusion in the oratorio of Negro spirituals was influenced by Eliot, and provides an analysis of the composer's own libretto through the lens of T.S. Eliot's essay ‘The Three Voices of Poetry’. Eliot's essay examines the number of voices in which the ‘I’ of a poem can speak, freed from the specificities of prose, and this article argues that Tippett, influenced by Eliot, harnessed the form of oratorio, freed from the specificities of opera, to allow it to speak in many voices.