In the 1960s, an interest in Jo zef Chominski's sonology theory was a lonely experience within European musicology. Its significance has been growing over the course of time, as has been the case with other investigative or artistic enterprises in the history of culture which were too radically avant-garde for their time. Today, it is the 'flagship' theory of Polish musicology, having caused a significant degree of resonance not only within the 'Chominski school', but also beyond it. An important premise within this tendency is the adoption of sonoristics as the so-called 'structural dominant' of a musical composition, in view of the loss of this function by the older, purely sound-based systems (major-minor, modal, 12-note etc.). Among the main operational categories (norms) of Chominski's sonological theory, the author regards as crucial the concept of the functional transformation of musical elements. Broadly understood, functional transformation refers to reshaping one musical element into another or, more precisely - changing the expressive values of a particular, relatively autonomous, musical element, into, in Chominski's words, complex expressive values. Writing about the new harmonics, Chominski said: 'the character of consonances, their interal dynamics, are a relative phenomenon, dependent on a number of co-factors, among them the manner of rationalising time, the treatment of the dynamic and articulatory techniques. There are no longer any chords, but 'vertical structures', in which the 'colouristic factor' plays a part. There are no melodics, but 'horizontal structures', co-created by sounds and agogic and purely motive moments. A sonological analysis thus offers individual investigation of the structure of compositions, where each of them separately is the result of its own norm-setting'. The article focuses on the systematisation of subjects for investigation by musical sonology (elements of musical sonoristics) from the point of view of the criteria of psychophysiological cognitive theory. In the final part the author discusses various works which have made a significant contribution to the development of Chominski's research, pointing to their open character which stimulates further research.