Do Pianos Mature?

[Richard Brekne]

John Musselwhite wrote:

> Hi Folks.
>
> We have been talking about whether a piano can "mature" and Richard brought
> up the point that scientific evidence of why or how this might happen
> seemed to be lacking. While perusing the "Wood Handbook - Wood as an
> Engineering Material" I ran across this on "creep and relaxation", which
> may or may not have something fundamental to do with the phenomenon.

Hi John.  I think before we get too far into such a discussion we need to
distinguish between a few things that this discussion necessarily touches on.

First we need to clearly separate the concepts of "deterioration" and
"maturing" from one another, and that probably isn't as simple as it may at
first seem. We know some things that happens to wood (in particular wood used
in our instrument making context) over time (some of which you mention below)
and to what degree and under what conditions these are actually to the
detriment of the instrument or not is really a discussion in itself As an
example one could compare panels that have been very evenly pressed over many
years in such a way as they maintain the original crown profile (albeit a bit
flattened out) vs those that have caved in at various points. It doesn't take
much thinking along these lines to find a good deal of unanswered questions,
again remembering the subjective nature of how piano sound judged in this
particular context.

Secondly we need to look at to what degree  our present knowledge base as to
what does happen to wood in instruments is complete. Does it fully explain all
the observations made by various individuals, and for that matter are those
observations made under strict enough rules to be useful for scientific study.
This is where I observe a distinct lack of science data to base our opinions
on.

As an example of this last I can refer to  part of a discussion Del and I had a
few months back where he stated that he expected a 100 year old panel (assume
the wood is in decent shape) to sound identical to a new panel under the
stipulation that both were rib crowned to the same degree, and their dimensions
were equal.  I know of others who say quite the opposite. Among these are
individuals who use old panels in this fashion routinely. I don't believe that
Del has actually done this himself. (he may correct me if I am wrong) But most
importantly I don't think ANYONE has done anything at all that resembles a
closely controlled scientific comparative experiment to look at any possible
differences there might be.  And there are many such comparisons, measurements,
etc. that would need to be made to arrive at enough knowledge to say we  *" <<
Know >>"* enough to cover and adequately explain most of the differing present
day "opinions".

Another example is how piano sound fares is say,  when a panel is subjected to
very even but very dry conditions over many years, visa vi very even but very
humid.  We can envision that in the one case the panel will be flatter, and the
stress between it and the strings plane will be less, wood gets stronger  yet
more brittle when dryer....,  how does compression set affect the structure of
this situation over say 50 years... etc. etc. These are questions that haven't
really been asked, nor is it suffice to simply pull conclusions based on what
we DO know and label these same scientifically sound.  That kind of thing may
be convenient to some, but it isn't good science.

While all the time keeping separate the basic issues of what constitutes
damage, what constitutes maturity, and what is simply change in physical
quantities.

Now nowhere in any of this is there the slightest hint of magic or mysticism or
the like. This is a stance with feet planted firmly in opposite plane. The
admission that we don't have enough data to make more then at best a hesitant
claim, or a tentative hypothesis. (
http://pespmc1.vub.ac.be/ASC/HYPOTHESIS.html ) And that goes for both "sides"
of the fence I seem to be standing on.

Just my view from the far North :)

RicB

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html