The laws of musical association will have to be established by a psychoanalytically trained musician. Probably a rhythm corresponding to one’s mood is often sufficient to cause a wordless tune to ‘occur’ to one. Sometimes a spirited waltz means: ‘I am so happy that I should like to dance.’ Every word, every situation awakens a certain feeling in people, to which there must correspond a neuro-physical process of definite quantitative proportions; and that music, by the combination of sounds and sound-sequences, must be able to create acoustic structures having the same quantitative relations as those of the nervous oscillations. Music was really only the product of emotion; man went on varying the notes until they corresponded to his moods; a natural musical instrument and its connexions with the central nervous system were the regulating factors in musical production.