explaining Pitch raise....

[Farrell]

I am no expert to answer these questions. And I will admit that in part I am
just using words that seem to make sense to the average piano owner -
although I do not think they are far from the complete truth. See comments
interspersed below.

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: <Tvak@AOL.COM>
To: <pianotech@ptg.org>
Sent: Wednesday, October 25, 2000 8:54 AM
Subject: Re: explaining Pitch raise....
>
> In a message dated 10/24/00 2:31:10 PM, mfarrel2@tampabay.rr.com writes:
>
> << when pianos
>
> have not been tuned for a period of time, the strings stretch over the
years
>
> and the piano slowly drops to a lower pitch
>  Is this true?

Wire stretches under tension - I assume it keeps on stretching over time -
but at an increasingly slower rate. (Yes, the wire gets thinner and longer.)

> Pardon my inexperience/ignorance for even asking the question,

No sweat Chet, I'm in the same boat.

> but I've often wondered exactly what happens when a piano goes flat.  If
> indeed the strings continue to stretch over the years, wouldn't the coils
> around the tuning pins on an old piano grow?

Yes they would.

> Wouldn't there be eventually be
> four coils around the pin?

Yes there would, although by the time the string stretched that much, it
might be past its breaking strength - which could be why you never see such
a thing (except on pianos originally strung that way).

> Or is it just that it's such a minute amount of
> stretching that it doesn't visibly show on the tuning pin?

That is my guess.

> I've thought that maybe the pin just slips back a bit over time.  But then
it
> wouldn't make sense that the pin would continue to slip back farther and
> farther, making the piano flatter and flatter as will happen on a piano
that
> hasn't been tuned in a LONG time.

Yea. My belief is that three things occur to make a piano go flat over the
years: 1) metal strings stretch under tension - quickly when first brought
up to tension, and then increasingly slower with time; 2) the pins will bend
and squish the pinblock a minute amount over time; and 3) the plate and
piano case/framework will very slowly and very minutely compress in reaction
to the string tension. I believe though that the latter two items occur a
bit when the piano is first brought up to tension, but not much a short
while afterwards. My (common sense?) guess is that with advanced age, the
reason pianos go flat is mostly string stretching.

Anyone else with any bright ideas?

> Tom S.