This research aims to determine the effectiveness in practice of traditional methods of playing with piano accompaniment, vocalization and verbal feedback, applied in the solution of intonation problems in string education, by conducting a comparative evaluation of these methods according to the grade level of the participants and their instruments as variables. One hundred twenty-six violin, viola and violoncello students at the 10th, 11th and 12th grades from Ankara, Bolu, Bursa Zeki Müren, İzmir Ümran Baradan and Manisa Fine Arts High Schools served as subjects for this study. Among the types of factorial designs, 3x3x3 between-groups factorial design was used in this research. Subjects were randomly assigned to experimental groups, the effectiveness of which was tested, with an equal number of instrument types and educational levels. In the research, "Intonation Scale-1", "Intonation Scale-2" and "Intonation Evaluation Form" developed by the researcher were used as data collection tools. Sound recordings of the subjects who performed the scales before and after the implementation of the methods were transferred to the computer and the frequency analyses of the samples were conducted through the “Melodyne Studio” software. Kruskal-Wallis H test was used to compare the mean ranks of the pre-test scores obtained in the frequency analysis, the mean ranks of the post-test scores, and the mean ranks of the difference between the post-test and pre-test scores; Mann-Whitney U test was used to determine which group was responsible for the significant difference that arose between the test groups as a result of the Kruskal-Wallis H test; and the Wilcoxon signed-rank test was used to test the difference between the pre-test scores and post-test scores. The findings of the study are that vocalization, verbal feedback and playing with piano accompaniment methods significantly increase the ability to play with correct intonation in all the experimental groups that represent instrument and grade levels. It has been concluded that the most effective method in terms of Intonation Scale-2 for 10th graders and Intonation Scale-1 for 12th graders is verbal feedback, and there is no significant difference in favor of any method in the other groups.

Keywords: Intonation, string education, vocalization, verbal feedback, playing with piano accompaniment