This article addresses issues of translation and transnational exchange, taking as a case study the two-pronged collaborative relationship between the French jazz singer, lyricist, and translator Mimi Perrin (1926–2010) and the African American trumpeter Dizzy Gillespie (1917–1993), whose memoir Perrin translated into French and with whom she collaborated on a 1963 jazz album. Perrin, who is the article's principal focus, founded the successful vocalese singing group Les Double Six in 1959 and then, after abandoning her musical career for health reasons in 1966, forged a new career as a literary translator. The article begins by examining her work as a translator of African American literature and demonstrates that her French edition of Gillespie's autobiography lacks some of the original's connotative cultural signification, in particular meanings conveyed through the book's use of black dialect. The article then turns to Perrin's work as a vocalese lyricist, which is notable in that she conceived of her lyricization of jazz improvisations as a sort of translation process, one that involved carefully selecting words in order to mimic the sounds of musical instruments. Her musical innovations are exemplified by a series of original French texts, set to Gillespie's music, on science fiction themes.