The importance and functions of musical architectonics in the creative process of a composer and performer are considered in the paper. The conceptual basis of the work is the definition of musical architectonics and classification of its types by V. Moskalenko. Specific features of musical architectonics compared to musical composition are revealed. The functions of architectonics in the musical-creative process of a composer and performer are defined. A method of studying the architectonics of a musical work is proposed. It consists of the study of indirect data, the features of musical material, the definition of the basic composition model and the dramatic relief of the work. It is emphasized that musical tempo-rhythm is an important means of materializing the “virtual” image of architectonics. In the sheet music, the composer fixed a certain tempo-rhythmic solution that clarifies the architectonic project of the work. Performers embody it in different ways, so the comparative analysis of performance versions is of particular importance. By identifying the differences in tempo-rhythmic solutions, the composer’s architectonic project is clarified, and the artistic potential of the musical work is revealed. Musical architectonics is an indicator of the composer’s and performer’s styles.