The article studies the artistic function of such a feature of the poet‘s rhythmic melody as the “flow effect” in the context of the analysis of Taras Shevchenko’s poem “Dolya” (“Fate”). The doctrine of famous American psychologist Mihaly Csikszentmihalyi, set forth in his book “Flow: The Psychology of Optimal Experience”, helps to understand the effect of flow as a factor of artistic energising. With reference to the creative experience of artists (composers, musicians, writers), the psychologist proves that they, being in a state of flow, that is, in a state of inspiration, create aesthetically valuable works. The ability for poetic improvisation, which often took on an explosive intensity, is one of the defining features of Shevchenko’s genius artistic talent. Poetic improvisation is a state of inspiration, a state of being in a creative flow, when the author expresses himself by creating an artistically sophisticated thing. The poet’s “Shchodennyk” (“Diary”) (the records of 7, 8, 9, February) testifies that the impetus for the creation of the triptych “Dolya” (“Fate”), “Muza” (“Muse”), “Slava” (“Fame”) was the emotional upheaval caused by the breakup with actress Kateryna Piunova, with whom he intended to start a family. Creating a triptych in the mode of improvisation was the way of self-expression, emotional “outpour”, meaning self-soothing. That is why the whole triptych has the mode of lyrical self-comprehension and most prominentlyit manifested itself in the first poem of the triptych “Dolya”. The analysis of the poem “Dolya” reveals a direct cаorrelation between flowing rhythmic melody and the means of expression called “stream of consciousness”. One of the important features of flowing rhythmic melody in the poem “Dolya” is related to its intonation contour, which is sensitive to the event developments. The key feature of the “flow effect” of the analysed poem is that all expressive components of the text (rhythmic, linguistic, compositional...) are realised in compliance with the principle of optimality. The flowing state of inspiration, the state of aesthetic exaltation experienced by the poet, due to the distinct flowing rhythmic melody is endowed with a uniquepower to influence the reader — to bring them into the same state of flow, giving them the aesthetic feeling experienced by the author. This is how the author-reader correlation is set into motion.