According to the American Music Therapy Association (AMTA), music therapy is defined as the clinical use of music interventions to address and support cognitive, emotional, physical, and psychosocial needs for individuals of all ages regardless of abilities. Research and evidence-based techniques are used in both group and individual sessions by a board-certified music therapist (MT-BC).
Source: American Music Therapy Association, 2005

A board-certified music therapist must complete an American Music Therapy Association approved curriculum or its equivalent.  Because music therapists work in a variety of medical settings, knowledge in areas outside of music is crucial.  Music therapy curriculum includes education in psychology, medicine, biology, social science, and behavioral science in addition to music.  This curriculum includes 1200 hours of clinical training.  After completing the curriculum, individuals must take and pass the national exam that is administered by the Certification Board for Music Therapists (CBMT).  Once the individual passes the exam and obtains the MT-BC credential, they are expected to keep their knowledge up to date through completion of continuing education courses as well as attending and presenting at state, national, and international conferences.