The use of psychotherapy is usually dependent upon people's abilities to speak about their conditions. Consequently, the use of verbal psychotherapy is very limited as a possible form of treating mental illness when patients' communicative and language abilities are reduced or lacking. This also applies to persons with severe multiple handicapping conditions who need support and treatment because of mental illness. The nonverbal approaches contained in arts therapies can offer a means of reaching this clientele. The special possibilities for expression that are contained in music therapy enable patients to develop a therapeutic relationship. In this way, mental disorders can become tangible. Pathways to change can then be experienced through the use of music therapy methods. The authors document descriptively the scientific evidence regarding music therapy and its established use in different fields of work. Music therapy is indispensable for the in-patient treatment of mental illnesses as well as for the treatment of persons with autism, severe multiple handicaps, neurological disorders and lack of expressive language. Research shows that persons with intellectual disorders are more likely to suffer from mental illnesses such as depression or psychosis. The German medical and psychotherapy councils do not fulfill their mandates for the care of patients with intellectual disorders or lack of expressive language. Because of this, different forms of arts therapies, especially music therapy, can be used to fill the gap. The proceedings of the 30th Symposium Music Therapy, held at the Freies Musikzentrum in Munich, provide a wealth of documents on the basis of which health policies can be discussed. The contributions show ways out of a situation that is the result of the blatant lack of psychotherapeutic care for persons with intellectual disorders. Additionally, those who live or work with persons with intellectual disorders receive a comprehensive overview of music therapy as an established procedure for the treatment of mental illnesses in this clientele.