The aim of this study is to determine how much the educational play named Piano in the Box developed by the researcher influences the musical success of fifth grade middle school students. As the method, the single-group pretest-posttest (retention-test) experimental design was used. As the data collection tool, a multiple-choice achievement test developed by the researcher was used after confirming its validity and reliability. First, the normality distribution of the data was determined through Shapiro-Wilk test, by using the SPSS 15.0. Concluding that the data were not normally distributed, any significant relationship between the results was examined by running the Wilcoxon Signed Rank test. The results were positive and in favor of the posttest and retention test. It was determined that the Piano in the Box game increased the success in learning music and made a positive change in learning the places of the notes on the staves and the piano.