Average age of residents living in National sanatorium Hoshizuka-Keiaien where people have past history of Hansen disease is around 80 years old at present, and many of them spend their whole days in watching TV or sleeping almost alone in their rooms. Therefore music therapy was introduced in order to improve their daily activities in our sanatorium. Singing, listening to music, playing the musical instruments, and dancing were performed, either in a group or individually. Reactivation of their brain function such as recollection, sense of unity and relaxation were expected. Improvement of cardiopulmonary function was also expected. Solidarity and relaxed state were observed by being with the other participants in the group therapy. For example, when using musical instruments, some participants with hesitation tried to use their instruments, and had good performance. They seemed to be satisfied and became confident with the musical instruments. Then their confidence and satisfaction activated the group. After the sessions, mutual conversation increased. These processes obtained a synergy effect, which means that a group affects of individuals at first and next alteration of individual behavior influences the group. We could observe a better effect in their motivation and activity in their daily life in the individual therapy. The music therapy was applied to the senior participants by the music therapist in this study. The participants could easily reinforce their mind and body through this therapy. Music therapy will be continued for the improvement of quality of life of residents in the sanatorium.