It has been claimed that Pavel Haas's string quartet ‘From the Monkey Mountains’ (1925) demonstrates the composer's alignment with the ‘Western’ musical avant-garde of the 1920s. However, Haas's avant-garde affiliations remain largely unexplained, as does the influence of Leoš Janáček, with whom Haas studied. Combining the methods of music analysis, semiotics and discourse analysis, I explain how Haas reconciled Janáčekian compositional technique with the ideas underpinning the contemporary Czechoslovak avant-garde movement known as Poetism. Focusing particularly on notions of the body, the grotesque and carnival, I propose an interpretative framework for and a reading of Haas's quartet ‘From the Monkey Mountains’. In doing so, I also illuminate the aesthetic and cultural context of Haas's music from the 1920s, which has received little attention in previous scholarship.