Pitch And Sympathetic Vibration

It is sympathetic vibration, manifesting itself in some instances in the

chest and in the head cavities, and in other instances almost entirely

within the latter, that gives to voices their peculiar timbre or

tone-quality--their physiognomy. It is by timbre that we distinguish

voices as we distinguish features. With instruments, differences in

quality of tone--differences in timbre--are due to differences of shape;

in case of instruments of the same kind, for example, violins, to

slight differences in form or to the grain, age and quality of the wood.

In the same manner, there are minute differences in the structure of the

vocal tract of different people; and it is especially the structural

differences between the resonant cavities of individual singers that

determine differences of timbre or quality. It is easy to distinguish

between tones even of the same pitch that come from a harp, a violin, a

trumpet, a flute or from the human voice. Between two violins of exactly

the same make, played on by the same person, there would be greater

difficulty in discovering differences in the quality of tone, although,

even if made after the same pattern and about the same date, there

probably would be minute structural differences that would differentiate

their timbre to a musical ear; while if, of two violins, one of the

instruments were new, and the other old, a musical ear probably would

immediately detect differences in their tone-quality.

It is easier to distinguish between voices even of the same range,

than between instruments of the same kind, because there is strong

individuality in voices. This is due to the fact that structural

differences between the vocal tracts of individuals are far more

numerous and far more minute than possibly can be introduced into

instruments. Moreover, the vocal tract, being part of the human body,

is subtly responsive to innumerable impulses and adjusts and readjusts

itself in innumerable ways. Instruments are made of material, chiefly

wood and metal, and, unlike the vocal tract, cannot change structurally.

The cornet, for example, is made of brass. The lips of the player

protruding into the cup can effect certain changes in shape, and changes

also can be made in the tube between the mouthpiece and the bell of the

instrument by pistons or valves. But these changes are absurdly small

in number compared with the structural changes of which the vocal tract

is capable, and commonplace in character compared with the refined and

subtle minuteness of the latter. For this reason, while there is a

distinct timbre for each kind of instrument, there are innumerable

timbres of the human voice--as many as there are voices, and all due

to the pliability of the vocal tract.

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

cooperation 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

reechoes 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.

Above the larynx is the pharynx, a space extending to the base of the

skull and opening into the mouth, and higher up connecting with the base

of the nose by means of two passages, the posterior nares, or back nasal

passages. The walls of the pharynx are permeated by a network of muscles,

so that this important space or resonance-cavity immediately above the

larynx is susceptible of numerous adjustments and readjustments in size

and shape; and as it lies with its back wall against the spinal column,

it also is susceptible and immediately responsive to suggestion from

the mind.

Another important resonance-cavity, indeed, the most important, is the

mouth, roofed by the hard palate which separates the mouth from the

nasal chamber, to which latter it also forms the floor. In the mouth is

the tongue, extremely mobile, and thus capable of materially changing

the size and shape of the mouth-cavity. Hanging from the rear of the

hard palate, like a veil over the root of the tongue, is the soft

palate; attached to which is the uvula. This hangs vertically down from

the soft palate and, if the rear end of the tongue is allowed to bulge

upward slightly, can be made to form with it a kind of valve, by which

voice is conveyed directly into the mouth-cavity without any of it

escaping up the posterior nasal passage; while the soft palate by itself

alone can be drawn up so as to touch the back wall of the pharynx,

completely closing the passage to the nose, so that a continuous curved

resonance-cavity is afforded from larynx to lips.

The soft palate is continued on either side by two folds known as the

fauces; and each of the fauces has two ridges, the pillars of the

fauces, between which are the tonsils. The pillars of the fauces enclose

muscular fibres which act respectively on the tongue, the sides of the

pharynx, and the upper part of the larynx, and thus aid in the necessary

movements of the vocal tract.

The nasal passage, divided into two ducts by a vertical partition, the

vomer septum, was referred to in the chapter on inspiration. The

so-called sinuses are hollow spaces in small bones on either side and

above the nasal passage and communicating directly or indirectly with

it. A question regarding the nasal cavity, including the sinuses,

suggests itself. Of what use is the nasal passage as a cavity of

resonance if, in order to prevent a nasal quality of tone, the passage

during voice-emission is shut off by the action of the soft palate, or

by the combined action of the soft palate, uvula and tongue? The answer

is, first, that it is not always to be closed off, because there are

times when a slightly nasal timbre in voice is desirable; secondly,

that even when the nasal cavity is shut off, the hard palate being

not only the roof of the mouth but also the floor of the nose, its

vibrations are communicated to the nasal cavity, but not directly enough

to give a disagreeable nasal quality to the voice.

From this survey it will be seen that the cavities of resonance along

the vocal tract may be divided into such parts as are solid, pliable

and movable. The solid parts are sharply resonant; they are, par

excellence, the resonators in voice-production; while a pliable part,

like the pharynx, although resonant in a less degree, is valuable in

adjusting structural shape to every condition that arises; and the most

movable parts of all, the tongue and the lips, probably wholly devoid

of resonance, have their great roles to play in effecting what may be

called wholesale changes in the size and shape of the mouth-cavity,

which could not be brought about by any other agencies less mobile.

The roof of the mouth, the teeth, the hard gums, the cones of the nasal

passage, and the sinuses are the solid portions of the cavities of

resonance. When Svengali gazed into Trilby's mouth and exclaimed,

"Himmel, what a roof!" he spoke from the depths of vocal knowledge.

For a highly arched mouth roof, especially if the tone enters the mouth

cavity from a wide, well-rounded pharynx, is of great value to the

singer. So is a fine, shapely, regular set of teeth, especially as

regards the upper front teeth, behind which the vibrations appear to

centre in so called "forward production." Cautiously brought into play,

the posterior nasal passage assists, with its resonance, the head tones

of the female voice and the upper range of male voices; but care must

be taken not to carry the tone up into the nose and thus give it a nasal


Some writers class the walls of the pharynx with the solid parts of the

vocal tract. But the walls of the pharynx are pliable, as already has

been pointed out, together with the admirable results to be derived from

their flexibility when under the singer's control. The movable parts of

or pertaining to the resonance-cavities are the soft palate with the

uvula, the fauces, the cheeks, the lips, the lower jaw and, most mobile

of all, the tongue.

The uvula often is too long, either by nature or through a disease

called prolongation of the uvula. It can be treated by astringents or

the elongation can be cut off, which usually is the most prompt and

efficacious way. The operator, however, in case the patient is a singer,

must calculate to a nicety just how much to remove, otherwise the voice

will suffer. There are isolated cases of deformed soft palate with uvula

so enormous that it cannot be raised. In such cases, one of which is

instanced by Kofler, a surgical operation being out of the question, the

patient simply has to give up singing.

Enlarged tonsils, whether from inflammation or other causes, also

have to be operated on, as their enlargement obviously hinders free

voice-emission. Even at its best the mouth-passage here is narrowest--and

called the "isthmus"--and nothing must be allowed to make it narrower

than it is by nature. The lips never should lie flat against the teeth,

since this would muffle resonance. On the other hand, the teeth should

not be bared, as this results in a foolish grin. The cheeks naturally

conform to the action of the lips. The lower jaw should be relaxed, which

gives the so-called "floating chin." When the lower jaw, and with it

the chin, is raised, the throat is tightened, and voice-action becomes

constricted. The "floating chin" does not, of course, mean that the chin

is to be thrust downward into the chest. In singing, as in everything

else, there is a golden rule to be observed.

It is obvious that the tongue also is a highly responsible member of

the vocal tract. Raise it too high, and you bring it so close to the

hard palate that the mouth becomes too small for free, resonant

voice-emission. The tone becomes wheezy. Let the tongue lie too flat,

and the mouth-cavity becomes too large and cavernous for tense, vibrant

voice-emission. The tone becomes too open. Let the base of the tongue

move back too far, and it will tend to close the pharynx and to check

free egress from the pharynx into the mouth, making the tone muffled.

Raise the back of the tongue until it touches the soft palate, and the

two combined close the mouth-cavity from behind, with the result that

voice is carried up the nasal passage and is charged with a disagreeable

nasal quality.

For every tone produced there is a special adjustment throughout the

entire vocal tract. These adjustments should, by practice, become

automatic, simple acts of swift and unconscious obedience to the will.

Then the question of "forward," "backward," or "middle" production,

according to the part of the roof of the mouth where the tone-vibrations

appear to centre, will become a matter wholly of the quality of voice

which it is desired to produce for any given emotional state. Forward

production--vibration appearing to centre a little back of the upper

front teeth--is, as a general thing, the best. Yet a voice brilliant to

the point of hardness can be mellowed by middle or backward production.

These are matters of judgment. But when I am told, as I was by a young

girl, that she was being taught to centre the tone-vibrations "back of

her eyes," all I can do is to throw up my hands and exclaim, "O

voice-production, what crimes are committed in thy name!" Yes--there

should be a Rescue League, or a Society for the Prevention of Cruelty

to Singers.