Research objective of the study is to determine the main indicators of the prognostic function of professional activity of the pianist-concertmaster in the vocal class in the pedagogical aspect. The methodology of the study is the methods of structural and functional analysis, systemic method and interdisciplinary approach to the study of music and performance, as well as the main provisions of vocal pedagogy. The scientific novelty of the study is a special approach to the professional skill of the concertmaster in working with vocal students, aimed at identifying the predictor of the pedagogical process. The prognostic function of the concertmaster’s activity is considered in the context of its pedagogical potential: as a possibility of a personality-oriented approach to the process of vocational training, emotional-psychological interaction with the vocalist, creative dialogue in the process of musical performance. Conclusions. Predictive abilities and skills are the most important structural component of the professional competence of the concertmaster, through which the multi-level interaction of the pianist and vocalist is carried out. This interaction ensures the expediency of solving the set goals and objectives in the student learning process and the success of the concert practice. The ability to predict is expressed at the following levels of activity of the concertmaster: mental (analytical, awareness, flexibility and perspective of thinking), emotional-psychological (emotional responsiveness and mobility of mental reactions), verbal (adequate verbal formulation of goals and practice), complex). The prognostic function of the concertmaster’s activity is a special systemic phenomenon, which is oriented towards the achievement of “artistic result”.