rations
essential to pitch and pass 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 assumes 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 button, 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 eve