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From: Mike Curtis
Date: Wed, 14 Jan 1998 03:56:38 -0800 (PST)
Subject: Re: Held Bends [A `bit' long!]

On Wed, 14 Jan 1998, Bobbie Giordano wrote:

>The one major influence on the vibration of the reeds is the relatively
>constant flow of air across them, by which tight eddies and currents of
>turbulence are induced as they flex back and forth across and through the
>slot in the reedplate. For each reed, according to its size, plasticity,
>shape, and perhaps other factors such as material, there is a natural
>frequency at which it responds best to passing air, and it may thereby be
>stimulated into action, chopping the air, and sending forth a compression
>wave, which may become audible with a strong enough air flow. What I do
>believe is that this air flow can be altered in several ways which will
>cause the reed to oscillate in uncharacteristic ways, resulting in pitch
>changes. In a dual reed system, there is another reed sharing the chamber
>with the reed that may also be so induced to vibrate at the same time.
>And furthermore, the combined vibration of these two reeds would seem to
>set up additional turbulence between them resulting in sympathetic vibra-
>tion akin to, and perhaps in reality, a form of mechanical resonance. Play
>a regular diatonic some time and check with a tuner as you dampen the less
>involved reed in the hole you choose to play, and watch the pitch alter
>before your very eyes. There is quite a bit of interaction.

I'm not questioning the factuality of this, but I tried it with my tuner
(Boss Tu-121, a good chromatic tuner) and an unvalved Oskar, using a 3D,
and found virtually NO variation in pitch when I hit a natural note, then
muted the unused reed. the TIMBRE varied a little as the "unused" reed
ceased vibration, but the pitch stayed within a couple of cents, either
side of the natural note. This is with my normal embouchure.

I next tried a much tighter mouth, verging on a prebend, and the note did
drop noticeably in pitch, but this was because the note was being bent,
due to restricted air pressure and NOT from the reed. I verified this by
keeping mouth position exactly the same but reducing air suction until
the bend went away.

Bends are not dependent on air pressure, as I can easily bend at any
volume.

I also tried it on a blow 3, using both embouchures, with similar results.

I also tried hitting a 3B like I was going to valved-blow bend it, and (of
course) it played right on pitch but when I blocked off the unused reed
(as a valve would), the reed bent wildly - just live a valved harp :-)

>This brings me to the fact that we DO alter our mouth positions when bending
>notes.

While I usually alter my mouth position, I can affect measureable pitch
changes using my throat, especially on valved notes. The "nannygoat"
throat vibrato is a good example of this, wherein the throat is used to
warble the pitch.

One way I get my bends to sound more like natural notes is to bend them in
the throat instead of the mouth.

I'm sure your measurements were just as you described them, and I'm not
arguing with them in the least. One of my ongoing hypotheses is that
there are at least two different ways of bending, and _I_ find them VASTLY
different and totally separateable. With your embouchure, etc., the pitch
lowered when you touched the "unused" reed (and I of course assume you
used a pitch meter and not just your ear.) With mine, it did not. I
don't at all see this as a contradiction, but actually reinforcing my
position (excuse the pun :-) to some extent that there are different ways
of playing and bending, and certainly showing that these things depend on
the player and technique as much as anything.



-- IronMan Mike Curtis
My CD "Doin' It All Myself" available in Tower, Blockbuster, Camelot, PX