Gertrude Stein and Virgil Thomson are known as much for their formidable egos as for their contributions to twentieth-century arts. That either could collaborate intimately with anyone is surprising. Yet Stein and Thomson did work together, magnificently so, most notably on the landmark opera Four Saints in Three Acts and the fanciful The Mother of Us All. This annotated collection of correspondence reveals the spark that existed between the two American masters over the course of their sometimes rocky friendship. The roughly 400 letters written between 1926 and 1946 record the fascinating nature of their partnership-their mutual excitement over evolving projects and their process for bringing together two often radical aesthetic sensibilities. The style of the letters is careful and forceful when the relationship is strained, but most often it is relaxed and affectionate. As a record of friendship the letters are particularly compelling, replete with love, support, and mutual fascination. Not surprisingly, the correspondence is stylistically remarkable-Stein being arguably the most innovative literary modernist and Thomson the author of crisp, insightful, irreverent music criticism, the most quoted of his century. In addition to their artistic partnership, the letters provide a revealing glimpse into their individual careers in the realms of literature and music, as they document a web of mutual friendships and the vibrant artistic community of the early twentieth century. The editors' notes contextualize this valuable exchange and add a layer of richness and accessibility. The volume will interest readers, critics, and scholars in music, literature, avant garde arts and modern culture more generally.