The present research attempts to underline the expressive values of the rhythm, regarded through prism of the musical art of Dimitrie Cantemir. This element of musical language gives originality to the Turkish sound background. Therefore, the concept of rhythm is imposed in Cantemir’s theoretic thought as one of key-components, in order to develop the art’s essence practiced by our musician. In this point of view, Cantemir reveals innovative spirit, formulating and giving value to an integrated theoretical system of musical culture unknown by Europe, that is produced in conditions where neither principles, nor the music orthography, conceived by well-known theorists in Islamic art 3-4 centuries ago, does not correspond to the reality. In Cantemir’s contradictions are pointed out dialectic unit between rhythm and melody – line of intonation determined by the sequence organized on a highest level (aesthetic, creative, emotional) of sounds of different heights an the primary factor of musical expression. One can consider the rhythm used by D. Cantemir in his compositions, to be measured with different development cycles, being based on two main values: optimes and fourth – generating fundamental duration of all rhythmical forms. In music, the stressed or unstressed sound emission (thesis or arsis) correspond with prime time(hronos protos). The constructive role of the rhythm is manifested through his tendency to symmetry and equilibrium, from a distinguishable periodicity to a perfect isochronous. The given arguments are brought to accredit an important idea and namely that: the rhythm in Turkish music, as it is revealed in cantemirien compositions, is a consubstantial size of basic morphological elements, determined physiologically and transposed in artistic discourse through acoustic fl ow pulsation, with a sequence more or less regular of the stressed periods , hence , the syntactic elements ( proto-elements, reasons, phrases, periods). By all this, is confi rmed the role of rhythm in musical art being considered as one of its fundamental constants.