The relevance of the investigation is justified by the lack of research into the first two decades of the life of the outstanding Ukrainian musician of the first half of the 20th century, Viktor Stepanovych Kosenko — an extremely important time when the foundations of the worldview and aesthetic beliefs of the future composer were laid. During this period, Viktor Kosenko, together with other family members, was in Warsaw, where he received a thorough general and musical education.
 The situation of another "white spot in domestic musicology" related to the artist's biography was created due to the lack of materials and documents, as well as the artist's personal belongings related to this period. The socio-political circumstances of Soviet Ukraine, in which Viktor Kosenko found himself in the 20s of the 20th century, became an obstacle to the preservation of sources and information of the relevant time.
 It has also been established that the composer's biography, which has been repeatedly reproduced in reference books and studies, is artificially constructed by him "at the demand of time". The scientific novelty of the study is the introduction into wide circulation of the socio-worldview and cultural panorama of the initial period of the artist's life. Therefore, the actual goal of the article is the reconstruction of the circumstances of the first twenty years of the composer's biography. The methodological basis of the research is the cultural-historical, biographical, as well as the method of source analysis, used to reproduce the initial period of V. S. Kosenko’s life path.
 Thanks to little-known publications of memoirs of the artist's contemporaries, as well as archival findings of modern scientists, it was possible to restore some facts of Viktor Kosenko's biography. The study focuses on the peculiarities of the educational and pedagogical process in the Warsaw Suvorov Cadet Corps, where the future composer studied. Emphasis is placed on the influence of many traditions, both national and social-worldview, with which Viktor Kosenko could come into contact during this period of his life. The atmosphere, traditions, way of life, as well as artistic impressions that formed the personality of the young musician and possibly influenced his further musical life are also considered.
 Conclusions. The multinational and multicultural environment of the earliest period of Victor Kosenko's life in Warsaw probably left an impression on the artist. Being at the intersection of cultures and traditions — a military and artistic environment with their inherent worldviews, a change in artistic and sociopolitical orientations at the border of the 19th and 20th centuries, the presence in everyday life of several national traditions (officially declared Russian, urban culture of Warsaw, preservation of Ukrainian origins in the family circle, a diverse circle of teachers and fellow students, etc.), could not but influence the growth of the creative personality of the Europeanized composer, who was open to other cultures. Tracing multi-level and multi-vector influences on the formation of creative ideas and their further specification looks like a promising direction for further research of the artist's creativity.