During their exile from Nazi Germany, an intensive exchange unfolded between the writer Thomas Mann and the forty-years-younger philosopher and musicologist Theodor W. Adorno. The two letters from Mann to Adorno, reproduced here, from 1943 and 1945, are associated with Mann's Doctor Faustus. Adorno was his adviser for questions concerning musicology and musical theories, in particular about the twelve-tone-technique developed by Arnold Schoenberg, which Mann used in his novel--without mentioning its creator. This led Schoenberg to accuse the writer of plagiarism--the novelist Enrique Vila-Matas refers to the story in his introduction. Mann responds to the charge with a lack of understanding, as he thought his principle of montage, in the sense of appropriation without identification of its source, and which he explains in detail in the later of the two letters, was "perhaps outrageous" but finally legitimate.Thomas Mann (1875-1955) was a novelist and Theodor W. Adorno (1903-1969) was a sociologist and philosopher.Enrique Vila-Matas (*1948) is an author living in Barcelona.