OVERTONES.
Overtones are tones above in pitch, but harmonic with the fundamental tone. They are caused by the vibration of the aliquot parts of a string as distinct from that of its whole length. These parts being shorter vibrate with greater rapidity, thereby giving a higher pitch than the fundamental note, though in perfect harmony with it. An overtone can be discovered by holding near one of the vibrating aliquot parts a chamber of the right size, form, and substance to reinforce the tone of one of these parts. This resonance would be loud enough to be distinguished from the fundamental tone.
The vocal cords act in like manner with the string described, and produce fundamental tones and overtones. In the vocal mechanism which produces the human voice, the resonant chambers are so graded in size as to correspond exactly with the fundamental note and all its overtones; therefore, an overtone as distinct from the fundamental tone is never heard, but reveals its presence only by enriching the voice.
METHODS FOR CULTIVATING THE VOICE.
FREEDOM AND RIGHT DIRECTION.
Freedom of tone is secured by the delicate adjustment and elasticity in the action of those parts which form the transient resonant molds. The hindrances to freedom of voice are produced by holding the vocal organs too rigid and close while forming these molds.
I have spoken of the deleterious effect upon the health caused by the misadjustment of the tongue in its relation to the pharynx, which results in “clergyman’s sore throat.” Another malformation of a resonant chamber is produced by holding a portion of the tongue too near the posterior portion of the roof of the mouth. A third is produced by holding the tongue too near the hard palate; a fourth by holding the tongue too near the front teeth. All these false adjustments are reported in throaty, rasping, and squeezed tones of the voice. The first object in the cultivation of the voice should be to establish habitual openness and freedom throughout the vocal aperture and this, too, by the shortest possible method. This method should consist, not in giving definite attention to first one portion of the vocal tube and then to another, but in securing a unified action of all the parts. By vocal practice, while holding the right mental concept, a clear and open passage from the vocal cords to the anterior portion of the nares can easily be secured.
DOMINANT CENTER OF THE VOICE.
The tone must be idealized with reference to place and form. The student should imagine the tone outside that resonant chamber of the nares most distant from the vocal cords. This will bring the consciousness outside that part of the nose which is between the eyes. The anterior portion of the nares is, so far as place and consequent resonance are concerned, the dominant center of the voice. My reason for calling this the dominant center of the voice is that when the tone is perfectly directed toward this chamber, all the resonant passages open freely through the entire nares, mouth, and pharynx to the vocal cords; and also the tongue has a tendency to relax its rigidity.