The aim of this study is to determine the possibilities and constraints of applying semantic isotopy, a concept developed in the area of semiotics with reference to language system and structure, in analysis of Orientalism as a way of presenting a reality that is referred to as the Orient in a musical work. The starting point is a review of acts of functioning of isotopy in semiotic text concept: from the original understanding of A. J. Greimas (semantic coherence of narrative text in the context of his theory of structural semantics), through the approach of François Rastier (strategic concept of interpretation within his theory of interpretative semantics) and Bernard Pottier (stability of semic feature, or isosemy of lexical-grammatical structures), to Umberto Eco’s concept (interpretive coherence associated with the concept of topic within the principle of textual cooperation). Determinants of adaptation of isotopy in musical semiotics are considered using the example of spectacularly extended fi eld of application of this concept in Eero Tarasti’s semiotic theory (or theory of musicological cognition of music) and his concept of discourse (musical one, and about music). The range of usefulness of isotopy is presented on the basis of methodological propositions of JeanPierre Bartoli and results of his research into Orientalism of the 19th- and early 20th-century French music. A description of consequences of examining Orientalism (oriental exoticism) as a semiotic system, assuming “language-likeness” of music, concerns conditions of “isotopic functioning” of musical exoticism. The conclusions underline a necessity for distinguishing between Orientalism and orientality due to the nature of semiosis in the case of music, and a need to verify the authenticity of “allochtonic units” (Bartoli’s “oriental semes” or “exosememes”) in a prospect of research in Orientalism as a phenomenon in the Western culture. These issues have also been emphasized in recent research on the musical consequences of cultural diffusion processes (manifestations of “occidentalising exoticism” in contemporary musical practice in the Middle East), in which the isotopy/isosemy is used as an objectifi ed transcultural analytical tool.