The Voice Part 3

(N. B.--In singing, the "true cords" are closely approximated.)

V, Ventricles. T, Thyroid Cartilage. C, Cricoid Cartilage. W, Windpipe or Trachea.

(N. B.--In STRAINING, the "false cords" are closely approximated.)]

The laryngoscope should not, in fact, leave the hands of the physician.

Invaluable for the detection of diseases of the throat which impair the voice and which have to be cured either by treatment or operation before the voice can be restored to its original potency or charm, its value in studying the physiology of voice-production and the functions of the vocal organs is doubtful. In fact, it is its use by amateur laryngoscopists that has resulted in the promulgation of all kinds of absurd theories of voice-study and in those innumerable pet methods of vocal instruction, each one of which may safely be guaranteed to destroy expeditiously whatever of voice originally existed. Fascinating as it may seem to the singer to examine his own larynx while he is producing a vocal tone--"during phonation," the physiologist would say--the value of the deductions formed from such observation may be doubted, if for no other reason than that the introduction of the mirror into the back of the mouth makes the whole act of phonation strained and the effects observed unnatural. In fact, as Mackenzie already has pointed out, although the laryngoscope is invaluable in the recognition and treatment of diseases which before only could be guessed at, "with the exception of certain points relating to the 'falsetto' register, it can scarcely be said to have thrown any new light on the mechanism of the voice." In other words, the instrument belongs in the hands of the physician, not in those of the singer.

The larynx, as I already have stated, is a small organ, on an average two inches long and one and a half inch wide. The reader can form a good idea of its location by the Adam's apple, which is its most forward projection at the top.

From the singer's point of view the larynx exists for the sake of the vocal cords--in order that they may be acted upon by certain muscles and thus relaxed or tightened, lengthened or shortened, or by a combination of these states properly adjusted to the note that is to be produced.

The vocal cords lie parallel to each other. The s.p.a.ce between them (the opening through which the air from the windpipe pa.s.ses up into the larynx) is called the glottis. With every loosening, tightening, lengthening or shortening of the vocal cords or other effect of muscular action upon them, the s.p.a.ce between them--the glottis--alters in size and shape. These subtle changes in the size and shape of the glottis are, as I shall expect to show, of great importance in voice-production. They form the first step in the actual creation of voice.

The numerous and subtle adjustments and readjustments in shape of which the larynx is capable could not be effected if its sh.e.l.l consisted of so hard and unyielding a substance as bone. Consequently, it has to consist of a substance which, while sufficiently solid to form a background for the attachment of its numerous muscles, yet is sufficiently pliable to yield with a certain degree of elasticity to the action of these. Nature therefore has built up the larynx with cartilage, or gristle, providing a framework made up of a series of cartilages, sufficiently joined to form a firm sh.e.l.l surrounding the muscular tissue, yet, being hinged as well as joined, capable of independent as well as of combined movement, and, withal, possessing the requisite degree of pliability to respond in whole or part to the extremely varied and often delicate action of the laryngeal muscles--muscles which indeed are required to be as practised and as sensitive to suggestion as if they were nerves.

The princ.i.p.al cartilage of the larynx is the thyroid or shield cartilage, named from the Greek _thureos_ (shield). It really consists of two shields joined along the edges in front (its most forward upper projection being the Adam's apple) and opening out at the back. The thyroid is the uppermost cartilage of the larynx and the Adam's apple is the uppermost portion of the front of the larynx. But as the shields open out back of the Adam's apple, they slope upward and at the extreme back each shield has a marked upward prolongation like a horn. By these horns, enforced by membrane, the thyroid cartilage and through it the whole larynx is attached to and is suspended from the hyoid bone, or tongue-bone. This gives mobility to the larynx and freedom of movement to the neck; and the larynx, while mobile as a whole, furthermore is capable of an infinite number of muscular adjustments and readjustments within itself.

At the back the lower edges of the thyroid rest upon the cricoid cartilage, which derives its name from the Greek _krikos_, a signet-ring. This is next in size to the thyroid. The broader portion, the part which corresponds to the seal in a signet-ring, is at the back. Attached at the back, the two cartilages do not, however, meet in front. Place a finger on the Adam's apple, slide it down a little way, and the slight depression there met with locates the front opening, covered with yielding membrane, between the thyroid and cricoid cartilages.

On the broader part of the cricoid--that is, on the part in the back of the larynx--and rising inside the thyroid are two smaller cartilages, the arytenoid or ladle cartilages, named from the Greek _arutaina_, a ladle. Though smaller than either thyroid or cricoid, they are highly important, because they form points of attachment for the vocal cords.

These (the vocal cords) are attached in front to the inner part of the angle formed by the two wings of the thyroid just back of the Adam's apple, and behind to a forward projecting spur at the base of each of the arytenoid cartilages, which for this reason often are spoken of as the "vocal process."

The vocal cords, as has been stated, lie parallel to each other, and the s.p.a.ce between them is known as the glottis or c.h.i.n.k of the glottis.

Above the glottis and on opposite sides are two pockets or ventricles, and above these are the so-called false cords or ventricular bands. The pockets are, in fact, bordered below by the vocal cords and above by the false cords. The false cords or ventricular bands (a name given to them by Mackenzie) are the lower edges of membranous folds that form the upper entrance to the larynx. Here are two pairs of small cartilages, the cartilages of Santorini and the cartilages of Wrisberg. Usually they are dismissed as of little or no importance. Yet they have, in connection with muscles located in that part of the larynx, their roles to play in those numerous adjustments and readjustments which, as I shall show a little later on, are of the greatest importance in voice-generation. For I consider, as I also will show, that the numerous, indeed innumerable, and extremely subtle and exquisite changes of shape of which the larynx is capable within itself, have much to do with the actual creation of the tone which eventually issues from the lips; although I believe this statement to be contrary to all accepted authority. For the present, however, I must content myself with this mere statement.

The larynx is protected above by a lid, a flexible, leaf-shaped cartilage, the epiglottis. The gullet, or food-pa.s.sage to the stomach, is situated behind the larynx and windpipe, and the function of the epiglottis is to close the larynx and to act as a bridge over which food pa.s.ses from the mouth into the gullet. But for the epiglottis, food might get into the larynx and thence into the windpipe every time we swallowed, with what distressing and even disastrous effect any one who has ever "swallowed the wrong way" well knows. When open, on the other hand, the epiglottis forms a beautifully smooth cartilaginous curve, over which the sounding air, the tone, as it issues from the larynx, is guided to the resonance cavities above the larynx, which are the cavities of the mouth and of the nose. While parts of these cavities are solid, like the roof of the mouth, other parts, like the soft palate, are pliable; while the tongue is so astoundingly mobile that it constantly can alter the resonance cavity of the mouth as to dimension and shape.

The larynx is swathed and lined with membrane and muscle. These membranes and muscles are named after the cartilages to which they are attached, between which they lie, or which they operate. There is no reason why they should be enumerated now. The function of the muscles of the larynx is stated by all authorities with which I am familiar to be twofold--to open and close the glottis (the s.p.a.ce between the vocal cords), and to regulate the tension of the vocal cords, because the vibrations of these are considered the determining factor of vocal pitch. Sir Morell Mackenzie, however, in describing the muscles of the larynx in a pa.s.sage couched in untechnical language, unconsciously gives a hint of another purpose for which the complexity of muscles in the larynx may exist. After speaking of the "innumerable little fingers of the muscles which move the vocal cords," he continues: "These fingers (which prosaic anatomists call _fibres_), besides being almost countless in number, are arranged in so intricate a manner that every one who dissects them finds out something new, which, it is needless to say, is forthwith given to the world as an important discovery. It is probable that no amount of macerating or teasing ever will bring us to 'finality'

in this matter; nor do I think it would profit us much as regards our knowledge of the physiology of the voice if the last fibrilla of tiny muscle were run to earth. The mind can form no clearer notions of the infinitely little than of the infinitely great, and the microscopic movements of these tiny strips of contractile tissue would be no more _real_ to us than the figures which express the rapidity of light and the vast stretches of astronomical time and distance. Moreover, no two persons have their laryngeal muscles arranged in precisely the same manner--a circ.u.mstance which of itself goes a considerable way toward explaining the almost infinite variety of human voices. The wonderful diversity of expression in faces which structurally, as we may say, are almost identical, is due to minute differences in the arrangement of the little muscles which move the skin. The same thing holds good of the larynx."

These are significant words. The distinguished physician who wrote them might just as well have said that the generally prevailing theory that in voice-production the muscles of the larynx exist solely to open and close the glottis and to regulate the tension and hence the vibration of the vocal cords, is incorrect. For they also exist in order to shape and reshape the entire larynx within itself according to the note to be produced, and the opening or closing of the glottis with the degree of tension of the vocal cords resulting therefrom is but one detail in the coordination of adjustments and readjustments which prepare the vocal tract to produce the tone the singer hears in his mind. Nearly every authority on the physiology of voice-production believes that the vocal tone is produced solely by the vibration of the vocal cords, and that the entire vocal tract situated above the vocal cords is concerned merely with augmenting the tone and determining its timbre or quality.

Let us examine this theory and ascertain how tenable it is.

To begin with, the term "cord" as applied to the vocal cords is misleading. It suggests a resemblance between the vocal cords and the strings of a violin, which are capable of great tension, or at least a resemblance between the vocal cords and the vibrating reed of a reed-instrument. In point of fact, the vocal cords are neither strings nor reeds, and are not even freely suspended from end to end or from one end like reeds, but are attached along their entire lower portion to the inner wall of the larynx. Therefore they are not cords, nor strings, nor reeds in any sense whatsoever. They are shelves composed of flesh and muscle, their substance resembles neither the catgut of which the strings of stringed instruments are made nor the cane, wood or metal of which the reeds of reed-instruments are formed; and the entire length of each cord is a trifle more than half an inch in men and a little less than half an inch in women. Almost every writer on voice appears to consider the term "cord" as applied to them a misnomer. They have been spoken of as membranous lips. "The vocal 'cord' is not a _string_, but the free edge of a projecting fold of membrane," says Mackenzie. Yet it is not only claimed but announced over and over again as a physiological fact that the human voice, sometimes sweet and mellow, sometimes tense and vibrant and with its great range, is produced solely by the vibration of two projecting folds of membrane, free only at their edges and at their longest only a little over half an inch in length.

At least one writer on voice-production, Prof. Wesley Mills, appears to have doubted the correctness of the old and oft-repeated theory.

"Allusion must be made," he writes in "Voice-Production in Singing and Speaking," "to the danger of those engaged in mathematical and physical investigation applying their conclusions in too rigid a manner to the animal body. It was held until recently that the pitch of a vocal tone was determined solely by the number of vibrations of the vocal bands, as if they acted like the strings of a violin or the reed of a clarinet, while the resonance chambers were thought to simply take up these vibrations and determine nothing but the quality of tone.... It seems probable that the vocal bands so beat the air within the resonance chambers as to determine the rate of vibration of the air of these cavities, and so the pitch of the tone produced." This at least shows dissatisfaction with the old theory and attaches some share of their due importance to the resonance cavities, but it still is far from describing the correct phenomenon of voice-production.

Show a lateral section of a larynx to a trumpet or horn player and he will at once recognize its similarity to the cupped mouthpiece and tube of trumpet or horn, the cup in the larynx being formed by the ventricles or pockets above the vocal cords. Extend the picture so that it includes not only the larynx but the resonance cavities of the head as well, and the cornet, trumpet or horn player will recognize the similarity to the tube of his instrument as it turns upon itself. The manner in which the lips shape themselves as the player blows into the instrument, the form and size of the cup, the gyration and friction of the air within it and within the bent portion of the tube, determine the pitch and the quality of the tone that issues from the bell of the instrument.

The shape a.s.sumed by the lips, which are capable of many exquisite variations in shape, conditions the form of the air-column as it enters the cup of the trumpet or horn. This I believe to be one important function performed for the larynx by the vocal cords, which Mackenzie, with an aptness he could not have appreciated, called the lips of the glottis. They are, in fact, the lips of the essential organ of voice, the larynx. If they are looked at from below they will be seen to be bevelled, and their resemblance to lips even more striking.

While, however, the importance of the vocal cords in tone-production has been overestimated, I should be going to the opposite extreme if I limited their importance to their function as the lips of the glottis.

Not only are they lips, but vibrating lips, their vibrations, however, requiring enforcement through the sympathetic vibrations which they generate within the cup of the larynx and in the cavities above. As lips, the vocal cords shape the air-column as it enters the larynx, to the required note; as vibrating lips--set into vibration by the very air-column to which they have given shape--they start the vibrations essential to pitch and pa.s.s them along into the cup of the larynx, which also has shaped itself to the note and where gyration and friction begin to reinforce the vibrations started by the cords. What is true of the cup also is true of the resonance-cavities. In other words, the entire vocal tract, from cords to lips, shapes and reshapes itself with reference to the tone that is to be produced, and what thus goes on above the vibrating cords cooperates to produce the effect formerly attributed to the cords alone.

The fact that the cup of the larynx subtly changes its shape for each tone produced, makes the hitherto obscure subject of registers of the voice, which many writers have written _around_ but none _about_, perfectly clear. The cup a.s.sumes what may be called a generic shape for each register, and then goes through subtle adjustments of shape for the different notes within each register. But this is a subject to be taken up in detail later.

The reader now will understand why at different points in this chapter I have emphasized the fact that the larynx as a whole and throughout all its parts is capable of numerous adjustments in shape, and that the same is true of the resonance-cavities. The vocal tract of an accomplished singer is capable of as many adjustments as a sensitive face is of changes in expression. This phenomenon is the vocal tract making ready to generate, vitalize and emit the tone suggested by the mind--mind pressing the b.u.t.ton, the physical organs of voice-production doing the rest.

CHAPTER VI

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; and 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 bra.s.s. 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 a.s.sumed by the larynx for pitch and the shape a.s.sumed by the resonance-cavities for quality, is ill.u.s.trated 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 gla.s.s 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 s.p.a.ce 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 pa.s.sages, the posterior nares, or back nasal pa.s.sages. The walls of the pharynx are permeated by a network of muscles, so that this important s.p.a.ce 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 pa.s.sage; while the soft palate by itself alone can be drawn up so as to touch the back wall of the pharynx, completely closing the pa.s.sage 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 pa.s.sage, divided into two ducts by a vertical part.i.tion, the _vomer septum_, was referred to in the chapter on inspiration. The so-called sinuses are hollow s.p.a.ces in small bones on either side and above the nasal pa.s.sage and communicating directly or indirectly with it. A question regarding the nasal cavity, including the sinuses, suggests itself. Of what use is the nasal pa.s.sage as a cavity of resonance if, in order to prevent a nasal quality of tone, the pa.s.sage 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 pa.s.sage, 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 pa.s.sage a.s.sists, 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 quality.

Some writers cla.s.s 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-pa.s.sage 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 m.u.f.fle 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 m.u.f.fled.

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 pa.s.sage 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.