The purpose of this study is to explore the effects of guided imagery activities using music on the relaxation and the mood state of music performers. For this study, 41 music performers over the age of 20 who were ahead of their ensemble concerts were randomly allocated to either the experimental and the comparison groups. The experimental group received the guided imagery activities with music intervention while the comparison group had no music intervention. The interventions were divided into eight sessions and conducted throughout the two weeks. The first session started on July 1st, 2019, and took place until August 12th, 2019, taking into account the various performance schedules of the participants and adjusting to their times. The SRSI(Smith Relaxation States Inventory) and K-POMS-B(Korean version of the Profile of Mood States-Brief) were used to measure the relaxation and mood state of both groups. The collected data were analyzed with the SPSS Statistics 20 program. The results of this study are as follows . There was a significant difference between the experimental group and the comparison group in the degree of change in the relaxation measurements. Moreover, there was also a substantial variation in mood state measures between both groups. Thus, this study successfully proved that guided imagery activities using music have positive effects on the state of relaxation and the creation of a positive mood over a short period for music performers. The study offered practical solutions in assisting music performers in overcoming mental and psychological challenges. As there are not enough research to help music performers, alleviate tension, and overcome their emotional difficulties, various interventions and further studies in the fields of music therapy need to be conducted and developed.