The article describes the theory of musical sonology, created by Józef M. Chominski over a period of some 20 years. The key concept of the theory is the category of sonoristics, defined by the author as 'moving to the fore the sound itself as the main means of expression and thereby a factor of construction'. The first part of the article describes the origin and evolution of the theory of sonology, from Chominski's first works in the 1950s, where he postulated viewing a musical composition as an actual sound event and taking into account performance resources when analysing it, to the full exposition of the theory in its mature form in the years 1976-78 (typescript entitled 'Podstawy sonologii muzycznej': (The Fundamentals of Musical Sonology) part. I. (no subtitle), 9 December 1976; part II. 'Systematyka zjawisk dzwiekowych' (The Systematics of Sound Phenomena), 1977; part. III. 'Forma' (The Form), 1978). The second part of the article discusses the basic elements of the theory of sonology, such as a general 'technology of sound' (questions of the source of a sound and the set of performance resources which can significantly enrich its timbre, from traditional instrumentation to percussion and mechanical music), problems relating to the systematics of sound (equivalence of sound material from different sources, dimensions of time and tempo, density and dilution of sound, sonoristic modulation and sonoristic possibilities of a formal continuum. The next section of the article deals with the reception and criticism of Chominski's ideas. While the theory of sonology is and has been of significance in Poland, the existing literature of the subject treats the postulate of investigating the structure of the actual sound of a composition as purely metaphorical. The reason for this is that Chominski's original idea reveals the paradox of drawing conclusions about the 'actual sound' on the basis of analysing the score, and not a particular musical performance. This approach results from the phenomenological conception of investigating the notational record of a composition as a projection of the composer's creative intentions. However, there does exist a need to extend the analysis of sound events to include their acoustic shape and psychologically conditioned perception, which undoubtedly require empirical research. Potential development of research into issues of musical sonoristics can be sought in a solution which will make it possible to identify experimentally physical-acoustic properties of timbre on the basis of its sonogram. Further musicological investigations would reveal the true value of Chominski's theory of sonology as a research method, and order and modify the conceptual apparatus he created.