to pass into the "middle" and
beyond that into the "head" register.

The breaks that occur in average voices at certain points of the scale
have established the divisions of the voice into registers. These breaks
can be accounted for on scientific grounds; and if the physiology of
voice-production had done no more than explain the why and wherefore of
vocal registers, it would have justified itself through this alone.

Suppose there were a man able to produce the entire male vocal compass,
from deepest bass to highest tenor. While for every note throughout the
entire compass there would be subtle changes in the adjustment of the
vocal tract, the following also would be true:--That, beginning with the
lowest note and throughout the first octave of his voice, the changes in
the adjustment of the vocal tract would not alter the general character
of the adjustment for that octave; that, on entering the second octave,
there would be a tendency toward change in the general adjustment of the
vocal tract; while, for the production of the remaining notes above, an
almost startling change in the adjustment of the vocal tract would take
place. The same would be true if a woman, capable of producing the
entire female vocal compass, were to begin with the lowest contralto and
sing up to the highest soprano tone. It is the general character of the
adjustment of the vocal tract for a certain range of notes in the vocal
scale that determines each register, the two principal changes in
adjustment causing two breaks in the smooth progression of the voice.

Allowing for the fact that the male voice is an octave below the female
voice, but in all other respects corresponds with it in range, the
adjustment of the vocal tract throughout each register is the same for
both men and women singers. There is, I fear, a prevalent notion on
the part of the musical public that each voice has its own separate
registers; that, for example, the registers of the soprano voice are at
different points of the scale from those of the alto, and those of the
tenor at different points from both of these. But this is not the case.
Always allowing for the octave difference between the male and female
voice, the registers for all voices are at fixed points of the scale and
are, or should be, sung by all voices with the same adjustment of the
vocal tract. A few examples will make this clear.

The lowest register for female voice is:

[Music: F3-F4]

that fo