Grist for the Mill

[Don]

Hi Terry,

The piano was tuned one month later after the 92 cent pitch correction and
was at 7.5 cents sharp. (second data line on my original email). The piano
was a small 42" upright that was 50 years old with an unknown tuning
history. The fact that the pitch correction "over shot" by 7.5 cents one
month later (with 7% more humidity) tells me that the piano had crown and
that the strings didn't stretch much in that initial month--this also tells
me the piano probably had been at A440 for at least some of its prior life.

I agree about the 2 cents per year--that's very clear on quality pianos
*with* full DC systems (including back/bottom covers), and especially so
with "quality" uprights.

I agree this piano exhibited good stability with average pitch change of
~0.15 cents per month (1.8 cents per year).

At 10:22 AM 5/13/2005 -0400, you wrote:
>Well, maybe I am missing the point, but I don't think so. If I am 
>understanding this pianos pitch/tuning history, in 1992 the piano was 70 or 
>so cents flat and was raised up to A440 or so at that time. Then today, 13 
>years later, the pitch was about 25 cents flat at A4.
>
>Again, I say that measuring pitch drop over time on a piano that just had a 
>pitch raise doesn't have much utility. It's not all that different from 
>restringing a piano and pulling the entire piano up to A440 - then measuring 
>pitch drop over time - likely would drop a bit more than 25 cents in 13 
>years. Yes, you can indeed do just that, but what does it tell you? Not much 
>except that things stretch and settle A LOT right after a restringing. Same 
>with a piano that just had a pitch raise - just less of a degree. I think 
>all that tells you is how unstable is an unstable piano.
>
>What is of interest, it seems to me, is the rate of pitch drop on a piano 
>that has been tuned to A440 for some years. I think this would give one some 
>insight into how stable a stable piano might be. My observations suggest 
>that most pianos, excluding humidity considerations, will drop less than two 
>cents per year.
>
>And actually, your 70-cent-pitch-raise piano wasn't all that unstable after 
>the pitch raise if it only dropped 25 cents in 13 years - that's just less 
>than 2 cents per year.
>
>Terry Farrell

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T.
Non calor sed umor est qui nobis incommodat

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