The article analyses the views of scientists on the phenomenon of stage and performance reliability. Interdisciplinary connections of the specified concept in various branches of sciences are established; it is characterised as an integral quality. It is emphasized that within the framework of psychological science such characteristics of the concept of stage reliability as faultlessness, durability, safety, stability, reliability are studied. It has been shown that stage reliability is a constant category in research that is inherent in research on the training of athletes, actors and instrumentalists. It is claimed that the level of formation and sustainability of stage and performance reliability depends on the psychophysical capabilities of the individual, the presence of personal qualities, the depth of acquired pedagogical and special knowledge, skills, abilities. Consolidation and improvement of the acquired musical-performing experience of the pianist-concertante during the stage-performing activity requires further improvement of the pianist-performer.