Abstract: The subject of this research is the peculiarities of manifestation of ontologization of musical thinking of Sofia Gubaidulina, through which mythology, religiosity, and “bivalence” in unity of the alternative worlds allow experiencing the logics of sensemaking of the composer within the paradigm of cosmogenic myths and natural beginning. It justified the authors’ attention to the examination of differentiation of sonoristic fabric of the choral oeuvres of the composer and two methods of vocal intoning – pure and with a savor of inhale – through amounting them to the categories of Cosmos and Chaos, characteristic to the artistic credo of Sofia Gubaidulina. The religious component of musical content of the composer substantiated the perception of dramaturgy of S. Gubaidulina’s works from the perspective of eschatological myths. However, the “bivalence” of S. Gubaidulina’s allows tracing the result of combining the diverse mythological models: “translucency” through the structural basis of the plot that requires determination of the own ontological status and system of myths of the cosmogenic type. Examination of S. Gubaidulina’s within the paradigm of cosmogenic myths enables adjusting the global opposition of the immanent and the transcendent, opposition of Chaos and Cosmos that is the basic ground for the structural logics of cosmogenic myths. Clarification of the ontological status of structural model of mythological thinking of S. Gubaidulina allows correcting the analytical parameters of interpretation of her musical compositions (on the example of the choral cycle “Dedication to Marina Tsvetaeva”) from the standpoint of the ancient cosmogenic models, manifesting in their sounding matter and structural methods of its organization the system of oppositions, within the foundation of which underlies the mytheme of natural-artificial (or natural-cultural).