The purpose of this essay is to explore how Thomas Mann’s Doctor Faustus: The Life of the German Composer Adrian Leverkühn As Told by a Friend (1947) creates the symbolism of the string quartet. It is clear from Mann’s diary and other writings that the novel is greatly influenced by a particular string quartet, Ludwig van Beethoven’s String Quartet in A Minor, Op. 132. In addition, several other string quartets appear, gradually developing the image of the musical discourse into a rich, microcosmic symbol for literature. Toward the tragic end of the novel, the musico-literary, aesthetic symbol stimulates the reader’s sociopolitical imagination and evokes a democratic society organized with extreme caution as a possible “breakthrough” and/or “hope beyond hopelessness” after World War II. The socio-political image can be examined more deeply in a larger context, for like Mann, other representative modernist writers, such as Virginia Woolf, T. S. Eliot, Carson McCullers, and Vladimir Nabokov, also published literary works closely interacting with the image of the string quartet. In other words, the symbolism of the string quartet in Doctor Faustus prompts a new exploration of modernist literature and calls up a practical image of the future.