The Voice: Its Production, Care and Preservation

by Frank E. Miller

It is the manner in which the numerous individual conformations of the vocal tract affect the overtones in the voice that makes voices different from each other; for the overtones are the chief agency in determining the timbre, quality, or physiognomy of any tone. Every tone consists of a fundamental or ground tone with its overtones. The fundamental tone determines the pitch; the overtones determine the quality, tone-color, timbre, or physiognomy of the tone.

The overtones, or harmonics, as they also are called, vibrate in certain simple harmonic relations with the fundamental—from twice to five times as often per second, sounding the octave above, the fifth of that octave, the second octave, the major third of that octave, etc. So important is it to the individual musical quality of tone, to secure the coöperation of overtones, that in certain large open organ

pipes, which are deficient in these, extra pipes of higher pitch and corresponding with the overtones of the fundamental note, are added and joined to the register. Overtones without the fundamental can be obtained on stringed instruments by stopping one of the strings and then touching it lightly at other points. The soft, sweet, ethereal character of the harmonics produced in this manner on a violin conveys some idea of the manner in which the many overtones of a note give it its distinctive quality.

In a way the overtones may be said to echo the fundamental, but the ear receives fundamental and overtones blended as one tone of a certain timbre. What that timbre is, is determined by the shape of the resonating cavity or cavities, the shape of which in turn is determined by the shape of the instrument, and in different voices by infinitesimal differences in the shape of various parts of the vocal tract. All instruments of a kind are made more or less on the same pattern and vary but little in shape. For this reason we have the distinct violin, horn, clarinet or pianoforte timbre, and so on down the list, but I repeat here that there are not such minute and individual differences between instruments of the same kind as there are between

voices of the same range, because there are no such minute and individual structural differences in instruments as in the vocal organs of individuals—differences that each individual can multiply ad infinitum by the subtle and delicate play of muscles acting in response to mental suggestion, art sense, inspiration, temperament, psychic impulse, or by whatever cognate term one may choose to call it.

There is little or nothing of psychology in Mackenzie's book, and yet, like other writers on voice-production, he appears now and then to be groping for it. Thus, when he speaks of the fundamental tone being reinforced by its overtones—by a number of secondary sounds higher in pitch and fainter in intensity—he adds very beautifully that every resonance-cavity has what may be called its elective affinity, or one particular note, to the vibrations of which it responds sympathetically like a lover's heart answering that of his beloved. "As the crude tone issues from the larynx, the mouth, tongue and soft palate, moulding themselves by the most delicately adaptive movements into every conceivable variety of shape, clothe the raw bones of sound with body and living richness of tone. Each of the various resonance-chambers reëchoes its

corresponding tone, so that a single well-delivered note is, in reality, a full choir of harmonious sounds."

Voice being, like instrumental tone, a commixture of fundamental and overtones, and the manner in which the composite conformation of collective waves strikes the ear being largely determined by the cavities of resonance, the control of these is of great importance to the singer. This control should, by thorough training, be brought to such a degree of efficiency that it becomes subconscious and automatic, so that the resonance-cavities shape themselves instantly to the note that is being produced within the larynx and, vibrating in sympathy with it, sound the overtones. The reciprocal principle of elective affinity between fundamental and overtone, between the shape assumed by the larynx for pitch and the shape assumed by the resonance-cavities for quality, is illustrated by the exciting influence of a sounding instrument upon a silent one tuned to the same pitch which, although not touched by human hand, sounds in sympathy with the one that is being played on. Even a jar standing upon a mantel-shelf, a globe on a lamp, a glass on a table, or some other object in the room, may vibrate and rattle when a certain note is

struck on the pianoforte. This is the result of sympathetic vibration. Thus, although vocal tone originates within the larynx, it sets the resonance-cavities into sympathetic vibration, and these produce the harmonics that give the fundamental tone its timbre; the resonance-cavities being to the vocal cords or lips what the body or resonance-box of the violin and the sounding-board of the pianoforte are to their strings, the tube of a cornet or horn to the lips, the body of the clarinet to its reed—the resonating factor which determines the overtones and through these the timbre.

Excepting the chest and trachea the resonance-cavities of the voice are located above the larynx. To the chest as a resonator the low tones of the voice owe much of their great volume. Indeed, the chest is such a superb and powerful resonating box that, if it resonated also for the high tones, these, with their inherent capacity for penetration, probably would become disagreeably acute. Therefore, nature, wise in this as in many other things, has decreased chest vibration as the voice ascends the scale.