Hearing plays may serve merely as a means for the satisfaction of acoustic impulses, or to give necessary exercise to motor apparatus, and, while this whole inquiry can not be said to penetrate further than to the antechamber of æsthetic perception and artistic production, an obvious distinction at once becomes apparent—namely, that between the receptive or hearing function and the production of sounds and tones. From the suckling’s delight in his own guttural gurglings to the most refined enjoyment of a concert-goer, from the uncouth efforts of the small child to produce all sorts of sounds, to the creative impulse which controls the musical genius, there is, in the light of history, a progressive and consistent development. (_a_) Receptive Sound-Play Pleasure in listening to tones and noises shows itself remarkably early, although, as is well known, the child is born deaf. Infants but two or three days old will stop crying in response to a loud whistle, and Perez has noted signs of enjoyment of vocal and instrumental music during the first month. Preyer reports of the seventh and eighth weeks: “There seems to be a marked sensitiveness to tone, and perhaps to melody as well, for an expression of the most lively satisfaction is discernible on the child’s face when its mother soothes it with lullabys softly sung. Even when it is crying from hunger a gentle sing-song will cause a cessation such as spoken words can not effect. In the eighth week the baby heard music for the first time—that is, piano playing. Unusual intentness of expression appeared in his eyes, while vigorous movements of his arms and legs and laughter at every loud note testified to his satisfaction in this new sensation. The higher and softer notes, however, made no such impression.”[40] The little boy in Sully’s Extracts from a Father’s Diary manifested displeasure at first on hearing piano playing, but soon became reconciled to it, and his mother noticed that while his father was playing the child became heavier in her lap, “as if all his muscles were relaxed in a delicious self-abandonment.”[41] Perez relates of a child six months old, on a visit to two aunts: “As the first of the young women began to sing he listened with evident delight, and when the other one joined in with a rich and melodious voice the child turned toward her, his face expressing the utmost pleasure, mingled with wonder and astonishment.”[42] This seems to indicate that agreeable tones and variety of movement are at first more appreciated than is the actual beauty of the melody. According to Gurney, appreciation of melody as such first appears in the fourth or fifth year.[43] It is otherwise with rhythm. Just as ethnology shows us that from the first inception of music rhythm was more prominent than melody, so it seems that the child too, as a rule, is sensitive to rhythmical cadence even when the beauty of melody is lost upon him. The regular ticking of a watch excites lively interest in the merest