[pianotech] Pitch Change (was: Grey market pianos, seasoned pianos, etc.)

[Gerald Groot]

I have read what has already been written in this thread, currently.  Ron,
I'm not going to sift through the archives.  The dissusion has been and
still is being presented now.  I'm merely adding to it as you are giving my
current thoughts on the matter again, as you are.      

Have YOU had the time to do all of these measurements yourself?  If so, I
don't know how you managed to find it let alone have the patience for it.  I
haven't nor do I have the desire to do so.  Taking measurements is not the
only proof available.  When does logic and common sense ever come into play
here?  

Yes, of course, everything will change from the sound board movements.  It's
"logical." :-)

As I asked, then, what else can it be?  If the piano were entirely made of
some material that did not flex in any way whatsoever, would the piano
strings still change pitch as they do?  



-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Saturday, April 03, 2010 10:35 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Pitch Change (was: Grey market pianos, seasoned
pianos, etc.)

Gerald Groot wrote:
> OK, a little play in words.......  In so many sentences you and others are
> indeed saying that it is not the main reason.  I am saying that I think it
> is. Has the rise and fall ever been measured?  

You mean instead of just taking it on faith? Have you ever 
calculated the string elongation change necessary to produce 
the tension change to take a string's pitch 5¢ higher or 
lower, and how much the soundboard would have to rise or fall 
to accomplish this at the low to vanishing downbearing angles 
we find in pianos? How about comparing downbearing readings 
before and after seasonal pitch swings? If the soundboard's 
moving enough to make the tensions change that much, the 
angles will change too.


> Doors and door jams expand and contract as much as 1/4" during each
seasonal
> change.  Sound boards do expand and contract a lot.  If it is not the
> expansion and contraction of the sounding board causing it, then, what is?

Read what has already been written in this thread, and chase 
it down in the archives. There's plenty of discussion.

Ron N