This received considerable coverage on Vocalist International and should
be accessable in the archives if they ever become available again.
Most interesting, thank you all,
John Blyth's description is very good I think. I'd just like to restate a few
principles that were made in some of the original discussion.
Harmonics of the fundamental frequency can only be produced in two ways.
One, generally held in abhorrence by the authorities of vocal production,
is by intermodulation. This is because it requires some rather gross
non-linearity to produce it.
The other is by square wave breath flow rates, with two sub groups of
symmetrical and non-symmetrical. That is, odd and even harmonics.
(In one respect this is a gross non-linearity too!)
Repeated total fold closure, is a description of
square wave air rate interruption.
Fold vibration that does _not_ include complete closure, implies
a fundamental deprived of harmonic association because the movement
of the folds cannot include the abrupt rate changes necessary to their
production. i.e. Falsetto.
Therefore the difference between head voice and falsetto clearly suggests
complete closure with relevant harmonic production for the head voice,
but not for falsetto. A low amplitude head tone would mean very low
amplitude related harmonics, and thus be easily confused with a similar
amplitude falsetto. This would suggest to me the need for on-set
exercises and downward sliding tones. But what would I know I'm
only a singer and a tenor at that.
In the symmetrical ; complete closure case, the odd harmonics produced
for a 220 Hz tone, the amplitude of which is taken as 100%, will include
33% 660 Hz
20% 1100 Hz (Hz means Hertz or vibrations per second.)
14% 1540 Hz (There would be no other frequencies.)
11% 1980 Hz
9% 2420 Hz Subsequent filtering of these frequencies will then either
block or pass and interface them to the external world.
The thing I cannot grasp in all this is how the so called singers
formant can be at constant frequencies apparently unrelated to
the relevant harmonics of the pitch being produced. Yet that is what
I seem to read here so often. An unpleasant aural prospect!
For some reason this brings to mind the problem some
singers have of not opening their words on the same pitch as the
subsequent vowel.
Regards Reg.
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