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 > You are missing the point--the thread is about pitch drop over time, so > this data is from my point of view is a perfect example of what happens > over 160 months. > > At 06:15 AM 5/13/2005 -0400, you wrote: >>I agree it would be interesting, but start with a decent STABLE AT PITCH >>(A440) piano - not a piano that you just did a 92-cent pitch raise on. >> >>Terry Farrell >> >>> 1992 01 pitch corrected 92 cents at A4 humidity 40% (including overpull) >>> 1992 02 floated pitch at 7.5 cents sharp at A4 humidity 47% >>> >>> Today? Pitch correction at A4 of 31.6 cents and worst note of 120 cents >>> humidity 29% (including over pull). >>> >>> Total pitch change over 160 months at A4 = 39.1 cents >>> >>> My "guestimate" is that for every 5% humidity change A4 drifts 4 cents. >>> This would give around 14 cents of the pitch change for the humidity >>> portion. >>> >>> Plugging that value in makes the pitch correction at A4 more like 25 >>> cents >>> in a mere 160 months between tunings, or about 0.15 of one cent per >>> month. >>> >>> I have no way to factor in humidity change for the worst note but if we >>> ignore it then 120/160 =~ 0.75 cents per month. >>> >>> I hope more folks will do this sort of analysis and post it to the >>> list--I >>> found Conrad's data *most* interesting! Particularly that the piano was >>> at >>> 436.7 on 01/03 and a year later was 436.7 again. Too bad there was no >>> measurement of room humidity to go with this! >> >> >>_______________________________________________ >>pianotech list info: https://www.moypiano.com/resources/#archives >> >> >>-- >>No virus found in this incoming message. >>Checked by AVG Anti-Virus. >>Version: 7.0.308 / Virus Database: 266.11.9 - Release Date: 5/12/2005 >> >> > > Regards, > Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. > Non calor sed umor est qui nobis incommodat > > mailto:pianotuna@yahoo.com http://us.geocities.com/drpt1948/ > > 3004 Grant Rd. REGINA, SK, S4S 5G7 > 306-352-3620 or 1-888-29t-uner > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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