"The idea of creating a story or a short novel, in which the hero-artist would have appeared as the modern Faust, occupied the mind of T. Mann at the beginning of his literary career. The realization of this bold plan was postponed for almost half a century, but the novel “Doctor Faustus” (1947) with all its genre ambiguity is primarily Künstlerroman, revealing three main typological signs of the works of this kind: its plot-composition center is the life story of the hero-artist, the novel contains a lot of reasoning about art, creativity and nature of inspiration, a significant place in it is given to the description of the works of the protagonist. This article is devoted to one of these descriptions and examines the oratorio of the fictional composer Adrian Leverkühn “The Lamentation of Doctor Faustus” as a kind of “musical ecphrasis”. Addressing to the history of the novel's creation shows what changes the original author's intention underwent, which was to present Leverkühn's last work as an incomplete fragment, turning the pages devoted to the “Lamentation” into one of the most vivid verbal descriptions of a musical work in the world literature. The use of the methods of comparative and intertextual analysis, which includes the reference to the musical and literary works, serving as the basis and the model for creating a large-scale description of the last work of the German composer, leads to the conclusion that the fictional oratorio is similar to the novel itself. This resemblance is manifested in the fact that both works refer to the original text of the legend of Faust, are in a peculiar attitude of denial to the preceding humanistic tradition and carry in themselves the pathetic element of the last, final work. Thus, this confirms the autobiographical character of T. Mann's late masterpiece, in which he reflects not only on the fate of the contemporary art, but also on his own works, looking back at the years devoted to the writing craft, summing up and leaving his Faustus with the hope of justification and salvation through the creative work."