At the same time the fact that these different sensations are experienced by the singer may be taken as the best possible evidence of the fact that there are definite differences in the method of tone production to account for them; and this view of the matter is in fact confirmed by the researches of physiologists.
There is no need, of course, for vocalists to concern themselves with the matter in detail, for the process involved is, of course, entirely (or almost entirely) automatic. But it is none the less explained by the physiologists quite clearly why there is, at a certain point, this difference of feeling on the part of the singer in passing from the lower notes to the higher ones.
Without going too minutely into the matter, the reason broadly stated is that the vocal cords are differently disposed in the two cases. Up to a certain point the successive tones are produced in one uniform way, and then above that point the method is modified; and it is this difference accordingly which is accountable for the distinctive sensations experienced by the singer—sensations, it may be added, which have been recognised and discussed ever since the art of singing has been studied.
Hence, it is quite a mistake to suggest, as has been done by some, that the whole notion of registers is a delusion. These different registers do undoubtedly exist, and it becomes one of the most important problems consequently to get rid of the “break,” or change in the tone quality, which occurs when the voice passes from one to the other. At the same time it does not follow that violent and artificial methods should be adopted for this purpose.
On the contrary, little else than steady and properly directed practice is required in the ordinary way to accomplish this. In fact if you get your breathing right and your tone production in general right, the register difficulty will probably solve itself. To put it in another way, if you ensure that each individual tone is right, the problem of the registers need not seriously trouble you; and this is a matter of paying attention to the general rules of sound tone production.
Special exercises are, however, usually given for the purpose of “equalising” the voice, as it is called, that is to say, for the purpose of ensuring a perfectly even and uniform quality of tone throughout the scale and avoiding the break at the change of register which has been referred to; and these exercises are no doubt useful.
Most of the best authorities are agreed that proper breathing has as much to do with the matter as anything, some even going so far as to say that the matter should not be mentioned to the student at all. This is perhaps a somewhat extreme statement, but the underlying principle is sound. And here, as always, the principle of absolute ease and relaxation and the avoidance of all unnatural muscular contraction or violent effort is at once all important.
The following is generally conceded to be a well-thought-out method of uniting the voice wherever the “break” occurs.
Sing this passage Messa di Voce ascending and descending, commencing where the break is first noticeable. If this is practised consistently for two or three periods of twenty minutes a day it should be effective in preventing this unpleasant defect. Begin firmly, using “ay,” “oh,” or “ee,” and swell out to fullest capacity. Then let the tone die away imperceptibly and be careful not to use falsetto. By doing the foregoing we have augmented the head tones to such an extent that instead of having falsetto, we have a head voice capable of being allied to the chest voice with practically no distinguishable break in the whole compass.