The point of greatest strain is generally, for both sexes, about this point, and many persons cannot sing higher than this—i.e., about
for males, and its octave for females.
It is to be remembered, as Madame Seiler has pointed out, that at the period of greatest perfection in vocal training, some hundred and fifty years or more ago, concert pitch was very much lower than it is to-day; so that to teach tenors to sing in one register up to
then, was quite a different matter from what that would be to-day. The old Italian masters were accustomed to train singers to the use of the falsetto, and whatever views may be held as to the desirability of the tenor using this register, so far as art is concerned, there can be no question whatever that physiologically it is easy, and one of the means by which relief may be sought from the high tension caused by carrying up the lower register.
The author, after a special investigation of this and other questions connected with the registers, came to the conclusion that the falsetto in males and the head voice in females are produced by a similar mechanism. In the high falsetto the vocal bands do not vibrate throughout their whole breadth, and there must be, for a successful result, in every case a feeling of ease, due to the relaxation of certain mechanisms in use up to that point and the employment of new ones.
Figs. 52. These figures are meant to convey through the eye some of the main truths regarding the nature of registers and breaks. The figure on the left applies to the case of one with three registers in the voice, and with the breaks only very moderately marked; the illustration on the right applies to the same person after training, when the breaks have become indistinct, almost imperceptible. For teaching purposes the author is accustomed to use a similar diagram, but in shades of the same color, the difference being rendered less obvious by intermediate shades between the register shades in the right-hand figure.