Although music as a creative manifestation of the human mind does not aim at social or utilitarian function, its materialized results may yet find wide application in the manifold use of this aspect of passive perception. This passive perception stimulates an active participation by the listener in whom it may provoke definite emotional reactions and mental modulations. If we think of music as the completed creation of one mind, we can understand how its perception may have a genuine influence on the listener’s mood and that it may be channeled into desired directions which takes the forms of adaptation and adjustment. This, in spite of the variety of tastes and reactions, can certainly be generalized within limits by scientific methods. Although I do not believe that music should be written for purely utilitarian reasons (and I am speaking not of the material advantages it may bring the artist, but of the aesthetics of creative art) I see no reason for not using any composition to such practical advantage as its application may offer. Music as an _art appliqué_ has been known since ancient times in many different roles, not all as laudable and noble as its use in healing. Its property of melodical expansion, propulsive character, rhythmical vitality, nervous insistence, harmonic intricacy, development in time rather than space, its wealth of moods (which extend from static calmness to wild exuberance with an enormous range of intermediary impressions, even in its abstract character of pure organized sound) provokes in listeners a response which is primarily psychological and emotional, but which frequently influences physiology and the nervous system.