Klarinet Archive - Posting 000357.txt from 1994/05

From: Kirby Fong <u745%sas.nersc.gov@-----.BITNET>
Subj: Clarinet materials
Date: Fri, 20 May 1994 21:40:33 -0400

In the last couple weeks there have been messages about the effect if any
on tone quality by clarinet materials and ligatures. I don't recall if anyone
questioned the effect of mouthpiece materials. Ideally, I should consult an
expert in musical acoustics to get some answers, but being lazy, I am resorting
to heuristics and personal experience. My personal observation is that the
clarinet body does vibrate; I can feel it in my fingers especially in the lower
register. Also the mouthpiece vibrates; just reduce the pressure of your
upper teeth on the mouthpiece to feel it. (I played a contra alto clarinet
one summer and didn't like it because it rattled my teeth.) Furthermore, a
contact microphone on a clarinet won't pick up anything unless there is some-
thing to pick up. Hence, neither the clarinet nor the mouthpiece are rigid
bodies. If these vibrate, then how they vibrate will be determined by their
elasticity, rigidity, density, or other physical properties. That is, the
material has an effect on the relative strengths of the different harmonics.
(Think about how different materials affect the sound of violin or guitar
strings.) The vibrations of the mouthpiece are probably affected also by how
tightly the ligature clamps or damps it. This is as far as I can reason in a
convincing manner. At this point you be convinced that the materials affect
how the clarinet and mouthpiece vibrate.
The next question is whether those vibrations matter. After all, the
sound of the clarinet is due primarily to its vibrating air column, not, as
far as I know, to the physical vibration of the instrument. Although it's
not relevant how the mouthpiece vibrates, it could be the vibrations of the
reed are not totally damped but are in fact partially transferred to the
mouthpiece by the binding of the ligature, and this could be an explanation of
why a ligature might make a difference. Anyway, the question is reduced to
the following: in a resonating cavity will vibrations of the cavity walls
affect the sound? For example, would the sound be noticeably different if the
walls were absolutely rigid? Attempts have been made to duplicate Stradivarius
violins. I believe it is possible for the duplicate to have nearly identical
shape and dimensions and to be played with the same strings and bows but still
have a different tone quality because the cavity (violin body) of the duplicate
just doesn't vibrate the same way as the Strad. Somehow, the duplicates aren't
using quite the same materials or haven't treated or cured them in a manner
resulting in the same vibrational characteristics. Now, I will be the first
to admit I know nothing about violin acoustics, so I may not have convinced
you (or myself) that vibrations in the walls of a cavity can affect the tone
(i.e. relative strengths of the different harmonics) of the sound from that
cavity. Another flaw is that the clarinet is really a tuned resonator while
I suspect the violin body is not. At this point I welcome anyone who can
contribute more information about acoustics, more appropriate insightful
observations, or more convincing gedanken experiments. While I have failed
to prove that materials and ligatures matter, I am inclined to suspect that
they can make small but perceptible differences.
I do not wish to hear arguments to the effect that gold flutes sound
different than silver flutes or organ pipes made from one alloy sound
different than pipes made from another alloy. That's not proof; that's just
the analogue to claiming that metal clarinets sound different from wooden
clarinets without offering any explanation why. I once had a math professor
who said, "if it's obvious, it ought to have a proof." This means no result
should be accepted as true because no one disagrees with it; it means a correct
proof must exist and we have an obligation to find it. There is proof by
deduction and proof by induction, but there is no such thing as proof by
analogy. Another approach is by experiment. If anyone could set up an
experiment where everything (reed, embouchure, air pressure, etc.) was the
same except for the material of the resonators and then run the waveform of
the sound through a spectrum analyzer, we might have conclusive evidence
(though not necessarily an explanation) that materials matter. I await
further information, insights, or observations from the KLARINET group.

Kirby Fong