In this study, the operability and teachability of the Orkhon script (tamgha writing) notation system, which was developed for the mouth harp instrument, was checked. The process in question was examined in three sub-dimensions. In this context, the structure of the notation system developed for the mouth harp instrument, the relationship between the Turkish Orkhon script and this system, and the effect of the system revealed as a result were investigated. The experimental process, which constitutes the main line of the study, was single-subject and was completed with posttest and retention tests. The experimental steps were spread over an 8-week period, one lesson per week, and were designed to teach the musical values of the Orkhon script in the notation system. The statistical data of the experimental test results were analyzed and evaluated. The results about the Orkhon script notation training and experimentation process are listed and finally, objective suggestions are put forward.