Acquiring knowledge and evaluating it in the form of evaluation, assessment and testing is one of the essential tasks of an organized educational system. Evaluation is a process that is related to the work of the teacher and the pupil. The article presents evaluation as a broader concept of assessment and testing which evaluates the learning process as well as the pupil's achievements. We emphasize the importance of the teacher's music evaluation system, which is to guarantee an objective evaluation of the student's work in the context of musical heterogeneity. A total of 186 teachers participated in the study, and a quantitative empirical descriptive causal nonexperimental method was used. The results confirmed the assumption that relevant professional didactic competences of teachers, as well as their experience and education, provide a more objective evaluation of the pupil's process-developmental and learning-oriented achievements in musical arts.