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.
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