ion of two such small bands as the vocal
cords must, in the nature of the case, be very feeble. It becomes
important for the reader to convince himself of the importance of
resonance in sounding bodies and musical instruments.
When the stem of a tuning-fork so small that it can be scarcely heard
when in vibration, except by, the person holding it, is laid against a
solid body, as a table, its sound is at once so increased that it can
be heard in the most distant part of a large room. When the same fork
is held over an empty jar of suitable size and shape, a similar but
much, less marked increase of its tone is to be observed.
If a cord of but moderate thickness be fastened at each end to a thin
piece of wood, say a split shingle, and a little block of wood, in
imitation of the bridge of a violin, be placed under the cord so as to
render it tense, we have the essentials of a stringed instrument, the
pitch of which can be made to vary by moving the block about and thus
varying the tightness of the cord. But the sound of such an improvised
instrument, produced by drawing a bow across the cord, is ridiculously
feeble.
In the actual violin the volume of sound, as well as its quality,
depends on the size, shape, and weight of the instrument. The strings
serve the purpose of causing the body of the instrument, the air
within it, and, in consequence, the air without, between it and the
ear of the auditor, to vibrate or move in a specific manner.
Similarly, the imposing size of the grand piano is associated
inevitably with loudness, as compared with a smaller instrument. A
violoncello must produce a larger tone than a violin, though not
necessarily one more intense.
These principles of resonance apply in the case of the singer and the
speaker. The bass and barytone produce tones of larger volume (as well
as different quality) than those of the tenor, because their resonance
apparatus is different in size and shape. It is true, their vocal
bands, their wind-power, and the laryngeal muscles are different--they
are not of the same size, etc.--and, in a more remote sense, this is
the cause of the differences in the tones they produce; but the
immediate cause is to be sought in the resonance mechanism, and, above
all, in the resonance-chambers.
It is true that when one speaks or sings, the chest, windpipe, and
larynx may be felt to vibrate, but the essential vibrations are
_supra-glottic_--above the vocal bands.
These
|