The relationship between music and the mind is obvious, but the nature of the relationship which has led some musicians to facile claims of artistry remains for most psychiatrists a tempting but obscure field. Most of the writing on this subject has been done by musicians and so-called results obtained with music in mental patients have been evaluated without medical guidance or the use of scientific method. Physicians are hesitant to accept new ideas which are not founded on unquestionable evidence. Enthusiastic laymen might call this reactionary, and they would not be entirely wrong. It is the reaction to the too rapid spread of folklore, cults, and nostrums which physicians have had to combat to keep medicine on the highest possible plane. It is the only tool with which they can protect the sick from unscrupulous or even well-meaning people who, for personal gain or with ill-founded conviction, promise cures by the citation of accidental or falsified results. By custom, ethics, and state laws the treatment of disease is the province of the licensed physician. The term “musical therapy” has been applied almost exclusively to the treatment of mental disease with music. The term “therapy” is derived from a Greek verb which means _to cure_. A cure can be practiced and determined only by a qualified physician, or under his direction. Claims can be made by anyone. To establish the curative value of any procedure, certain criteria must be observed. In the first place, the disease must be accurately classified so that the affliction of a series of patients can be scientifically grouped for study. Next, the therapeutic agent must possess qualities of constancy which permit controlled dosage. Last, the proper administration of the agent in the same disease condition must show a reasonably high percentage of results which can be proved to be of value in the control or elimination of symptoms or disease. Until a relatively short time ago, the causes of most disease conditions were unknown and illnesses were named according to their superficial characteristics. Most newly named diseases are designated by the agents which cause them or by the variations from normal found in the tissues of the body they affect (pathology). In psychiatry, most diseases bear the names applied to their outward appearances. A simplification of terms places mental disease into three general classes. Psychoses, Psychoneuroses, and Behavior Disorders. The subdivisions of these classes are not universally accepted and the musician who works in a mental hospital will soon become acquainted with the locally practiced terminology. As a guide to vocabulary rather than an introduction to psychiatry, a brief review of some of the prominent symptoms of mental disease will be enumerated. The scientific material is based on Noyes’[62] excellent text.