Problem statement. The author performs a hermeneutic analysis of Cossack-musician image from the Ukrainian folk paintings “Cossack Mamai” of the canonical type. It is proved that the painting symbolism is based on the reproduction of transitional rite, which has sources to the Indo-European, Old Iranian (Scythian-Sarmatian-Alanian-Osetian) and Old Slavic layers of culture of the Ancient Ukraine.The aim of this paper is to carry out a hermeneutic analysis of the Cossack- musician image from the Ukrainian folk paintings “Cossack Mamai” of canonical type, to establish an earlier version of the painting plot, to determine the main and auxiliary, synergetic-acting motifs-symbols.Research methodology. The author applies the comparative and historical and logical methods used for the comparative study of the transitional cycle rituals of the ancient nations from the Indo-Iranian and Old-Slavic worlds.Results. Based on this research results it can be concluded that “Cossack the Musician” painting plot reflects the cultural signs transcoding of the historical past — the ancient Iranian (Scythian-Alanian-Osetian) myths and epics. They, being generated within the territory of Ukrainian lands, reflect the transitional rite. Cossack-musician image preserves the ancient spiritual historical symbolic code of the Ukrainian people and relics of its ancient mythical-religious believes. The semantic centre of the paintings includes two synergetic motifs-symbols: 1) Cossack-musician with priest-shaman attributes — a musical instrument, a bowl, a sacred headpiece, and 2) a horse tied to a thrusted spare with its spike up, which is an analogue of the World Tree (both are symbols of transition). The musical instrument in Cossack’s hands is a key motive in the composition structure and acts as a mediator, combining the three areas of the universe and other motifs into a single narrative text; it gives grounds for interpreting the hidden meaning of the reproduced event as a reflection of the transitional rite (death — revival).Novelty. It is proved that the invariant symbols of “Cossack Mamai” paintings contain the relics of the Scythian-Alan-Ossetian transitional rites, which are reflected in the content of folk paintings. It is determined that the instrument in Cossack’s hands is the kobza, not the bandura.The practical significance. The material in this article can be used in the academic programs of the university courses for cultural studies, art studies, instrumental studies, ethnomusicology and the history of bandura art.Key words: Ukrainian folk picture «Cоssаck Маmаi», cоssаck-musician, rite of the transitional cycle, kobza.