Dear Vocalisters:
A series of posts have appeared in the last weeks regarding use of
chest voice in various musical styles. To my knowledge, none of
these posts have suggested that a particular kind of chest voice
should be used in all musical styles but, instead, have become
concerned with the use of chest voice as a proper vocal technique.
Chest voice occurs when the vocal fold muscles (vocalis muscles) are
active and provide a resistance to the stretching action of the
crico-thyroid muscles. The resultant tension between these muscle
systems produces a phonated sound that is rich in harmonics and, when
produced in the possible frequency range, a strong fundamental.
Adjustments of the vocal resonating spaces (vocal tract) allow the
singer to make tonal changes in this phonated sound but these
resonance adjustments do not change the vocal fold structure that
produces the phonated sound.
In contrast, in high voice the vocalis muscles are no longer active
and the necessary resistance to the stretching actions of the
crico-thyroid muscles is now provided by the vocal ligament which is
near the surface of the vocal fold. In effect, the vocal folds
muscles (vocalis) are no longer a part of the phonational structure
of the voice. This produces a phonated sound at a higher frequency
with a pronounced fundamental and a harmonic spectrum that, although
complete in pattern, is necessarily more spread out because of the
higher fundamental frequency that is present.
(Note: Because partials of the fundamental occur as increments of the
fundamental, the higher the fundamental, the more space is present
between each successive partial. It is for this reason that female
voices have a more difficult time locking onto the correct overtone
resonances for a given pitch as compared to male voices which have
more partials available for the process as well as having partials
that are closer together.)
As the singer moves from chest voice into high voice a transition
must occur somewhere in the process such that the vocalis muscles
will gradually reduce activity and the vocal ligament will assume the
work previously done by the vocalis muscles. How this is
accomplished and where it is accomplished is the basis of most of the
differences in vocal techniques between various vocal styles and even
within a given style but in different countries. In addition,
modification of the resonance spaces or vocal tract can either assist
or detract from the process of making this vocal fold adjustment.
This is so because the acoustic properties of the sound in the vocal
tract can provide a kind of acoustic support for the vocal folds
throughout the transition range.
The area of transition from chest voice into head voice and back
again has been given a multitude of names such as middle voice,
passaggio, turn over area, mixed voice ( in all its various forms
such as low mix, high mix, etc.) but regardless of the name the vocal
function that must occur is basically the same.
Pneumatic pressure on the vocal folds (breath pressure) will also
have a direct effect on the ability of the vocal mechanism to make
the transition from chest voice to high voice. Even the best
produced voice will find it more difficult to make a smooth
transition from chest to high voice while singing loudly and a much
more easy time of it while singing softly. If the particular singing
style requires or assumes amplification, the singer is less likely to
sing loudly and more easily able to make the transition between chest
and head. If the particular singing style requires or assumes no
amplification, such as in opera, the singer will find the transition
from chest to high voice a much more challenging hurdle. There are
many devices that have been developed by the acoustic singer to make
this transition easier and one of them is to not use the lowest forms
of chest voice within the particular aria or scene being performed.
But this does not preclude the use of all forms of chest voice within
the vocal scope of music theatre, including opera.
As singers and voice teachers we most often concern ourselves with
techniques that work regardless of why they work. The danger in this
approach is that it is possible to develop a technique that limits
the vocal potential of the singer and does not address the vocal
demands of a particular singing style. At its worst, this pragmatic
approach to singing can even provide a technical solution which is
contrary to the organic physical functioning of the vocal mechanism.
--
Lloyd W. Hanson
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