To make a decision for music and musical instruments selection in music therapy sessions is based on the individual needs and concerns of a child. To apply the concept of music therapy in the special education field, teachers or professionals must have at least one functional instrument leading or accompaniment skills, while continuing to develop musical ability and appreciation to facilitate diverse music selection. From the author's practical experience in music therapy, this article will provide the principles and methods of selection and application on music and musical instruments. Hope to help practitioners who are interested in music therapy to conquer the difficulties in teaching.