Abstract: The aim of this research is to trace back director functions in a professional activity of a piano concertmaster. The subject of the research is the work of a piano concertmaster with an ensemble composition using the stage production techniques. The author of the article analyzes a director method of working with a text, stage movements, expressivity, acting areas, etc. Kalitsky pays special attention to the organisation function of a director and piano concertmaster that is necessary for creation of a single artistic style. The author also touches upon the duality of acting and directing in an activity of a piano concertmaster. The author uses the comparative analytical methodology to analyze the activity of a director and concertmaster. He demonstrates that the ensemble model used to organize the sound and stage space is one of the most important functions in a professional activity of a piano concertmaster which can be achieved only through understanding and perception of directing techniques used to produce a stage action. The author of the article emphasizes the need in a directing approach to stage production and work of a piano concertmaster not only with ensemble partners but also for individual studying a musical text in factor, dynamic and agogical terms. Kalitsky underlines the importance of the solo performance training of a pianist for success as a director of a musical ensemble. Application of the research results in a professional activity of a concertmaster will give a better understanding of not only artistic targets faced by him or her but also organisation functions of a pianist in a musical ensemble. The author concludes that there is a need in ajdustment of current programs of piano concertmaster training in order to teach them director principles of being a pianist in a musical ensemble as well as independently seeking his or her artistic ensemble solutions.