Klarinet Archive - Posting 000795.txt from 1999/05

From: "Edwin V. Lacy" <el2@-----.edu>
Subj: Re: [kl] blow out - AND the effect of materials!
Date: Mon, 17 May 1999 04:38:44 -0400

On Sun, 16 May 1999, Dan Leeson: LEESON@-----.edu wrote:

> And what is absolutely fascinating about this discussion every time we
> have it is the passions that it raises in people. This one and "dark
> sound" are probably the source of more energy being expended in
> defense of one's views than almost any other topic.

Yes, and I would say that in addition to the two you list, another one
certain to raise blood pressures and adrenaline is "the effect of
materials" on woodwind performance characteristics. And now, I'm going to
mix two of those controversial subjects in the same message! Everybody
get the Prozac ready! ;-)

Earlier in this thread, I weighed in on the topic of blow out, introducing
the matter of depolymerization to the discussion. Now, for a person such
as myself, who is inclined also to accept the position of acousticians
that the material from which the instrument is constructed has relatively
little influence on the way it sounds, it might at first seem somewhat
contradictory to also claim not only that blow out exists, but also that
the phenomenon would have an effect on the deterioration of the tonal and
response characteristics of an instrument.

In other words, if depolymerization occurs (and it does) and if that
contributes to changes in the instrument which we characterize as "blow
out," and if one accepts the position that the material has a small
influence, almost an infinitessimal one, on the musical characteristics of
the instrument, then depolymerization alone, and the results of it on the
material, should not have much effect on the musical results.

But, the reply would be that the culprit is *dimensional changes*. We
discuss this periodically all the time on all the woodwind lists, so I
don't remember if I'm repeating myself on KLARINET, but briefly, the
position of materials scientists could be summarized in a very elementary
way thusly: All rigid materials capable of sustaining structures such as
musical instrument bodies, (except metals and ceramics), consist of long
chains of carbon atoms, bound together by molecular structures called
"polymers." Over time, these polymers break down, causing ever shorter
chains of carbon atoms. This results in fundamental changes of various
sorts in the qualities and characteristics of the material.

But, it is not my position that this process or the changes which it
brings about are alone responsible for the phenomenon which some call
"blow out," but rather that there are several factors, including
polymerization, which might cause dimensional changes in an older
instrument. Others might include the effects of repeated swabbing,
cumulative changes due to many wettings and dryings of the wood, changes
which might occur due to the effects of prolonged atmospheric, humidity
and temperature variables, the natural tendency of wood to change at
different rates in different axes according to the eccentricities of its
own grain, the effects of the response of the wood to the forces applied
to it in construction of the instrument, etc.

As some have pointed out in this discussion, what we need is a set of
detailed and accurate measurements of an instrument near the beginning of
its useful life span, and then re-measurements of the same instrument
after 20, 40, or 60 years of use. Another thing that would be useful, but
impossible to achieve, would be a comparison of the playing
characteristics of the new instrument and the same one as a "senior
citizen." In the latter case, besides the long time span, there are far
too many variables to be able to come to any supportable conclusions.

Does anyone have an old clarinet and exact measurements of it as a new
instrument?

Ed Lacy
el2@-----.edu

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