Turning now to the muscular adjustments of the vocal organs, these adjustments are seen to be independent of conscious guidance. When a tone is mentally conceived the vocal organs adjust themselves, in response to some mysterious guidance, for the production of the tone. The vocal cords assume the appropriate degree of tension according to the pitch of the tone to be sung. Both the quality of the tone and the vowel are determined by the combined adjustments of the laryngeal muscles and of the muscles which fix the shape and size of the resonance cavities. The power of the tone is regulated by the force of the breath blast; for each degree of power some special adjustment of the vocal cords is required.
All these adjustments are executed as one concrete and individual act in response to the volitional impulse contained in the mental conception of the tone. The tone is conceived as a concrete whole. It is not normally broken up mentally into its four aspects of pitch, quality, vowel, and power. True, each one of these four characteristics of the tone may be separately considered by the singer. So also, to a certain extent, may the adjustments of the vocal organs be performed with special reference to one or the other characteristic of the tone. But in every case the muscular contractions are performed without direct conscious guidance. Whatever be the character of the tone mentally demanded, the vocal organs instantly adjust themselves to produce the tone.
What is meant by saying that the muscular contractions are performed without conscious guidance? Does this mean that the singer is unconscious of the muscular contractions? Not at all. Muscular sense informs the singer, more or less distinctly, of the state of contraction or relaxation of the various muscles of the vocal organs. The singer always knows fairly well the condition of the various parts of the vocal mechanism. What is meant is this: The singer does not consciously direct the vocal organs to assume certain positions and conditions, and does not instruct the various muscles to contract in certain ways. The singer does not need to know, and in fact cannot know, what muscular contractions are required to produce any desired tone.
Some connection exists between the organs of hearing and the vocal mechanism. That this connection has a physical basis in the nervous structure is fairly well established. "The centers for sight and for arm movements, for instance, or those of hearing and of vocal movements, have connecting pathways between them." (Feeling and Will, Jas. M. Baldwin, 1894.) The psychological law of tone-production is that the vocal organs adjust themselves, without conscious guidance, to produce the tones mentally conceived. In actual singing the practical application of this law is that the voice is guided by the ear.
This guidance of the voice by the ear is incessant. It must not be understood that the mental ear simply conceives a single tone, and that the vocal machinery then operates without further guidance. All the characteristics of the vocal tones,—pitch, quality, and power,—are constantly changing. These changes require corresponding changes in the muscular adjustments. The muscular contractions in turn are guided by the demands of the mental ear. As a psychological process, singing may therefore be analyzed as follows: The singer mentally sings the composition. In response to the ever varying demands of the ear the vocal organs adjust themselves to produce actually the sounds thus mentally conceived. The singer listens to these sounds and at every instant compares them to the mental conception. If the tones actually produced fail to correspond exactly to those mentally conceived, the singer instantly notes this variation and bids the vocal organs to correct it. The ear has therefore a dual function in singing. First, the mental ear directs the voice in its operations. Second, the physical ear acts as a check or corrective on the voice.
To sum up the psychology of tone-production, the singer guides or manages the voice by attentively listening to the tones of the voice. This is the only possible means of vocal guidance. The voice and the ear together form one complete organ.
But we are still apparently as far as ever from the specific meaning of the correct vocal action. That the voice instinctively obeys the commands of the ear may be true theoretically. In actual practice we know that this does not by any means always occur. Singers are often unable to get the desired results from their voices, even when they believe themselves to rely on the sense of hearing. There must therefore be some influence which under certain conditions interferes with the operations of the vocal organs. The problem of tone-production is thus seen to be one of psychology. It narrows down to this: What can interfere with the normal action of the voice and prevent the vocal organs from instinctively responding to the demands of the ear? A satisfactory answer to this problem will be found only by a consideration of all available knowledge of the voice, both empirical and scientific. This forms the material of the final division of the present work.