>I may be wrong (always a distinct possibility) but didn't Dr. Sanderson >and others test this whole business and determine that all changes to >the piano caused by changing string tensions are immediate? I agree. I don't see how plates and frames will be shifting significantly with a minor pitch adjustment. There is a very definite factor, however, that is almost universally ignored, and that is strings rendering through bridges. We most likely aren't going to get string segment tensions on opposite sides of the conventionally pinned bridge equal with just a normal and/or usual tuning. It isn't going to happen, as we have no way of determining what those tension differences are, and there is enough friction across that bridge to allow for a considerable difference (in resulting pitch). Over a couple of days, especially with play, segment tensions will more nearly equalize and the tuning will drift. Doing the second tuning a week or so after the pitch correction will leave a better tuning for a longer time, but you need a customer who is willing to pay for a nicety they may very well not be in a position to appreciate, given that the piano was allowed to get into a condition of needing a pitch correction before it was tuned this time. There isn't any ONE, ABSOLUTE, DEFINITIVE ANSWER, but I'm convinced that friction at the bridge is a much larger part of this than is typically given credit, and very likely the major cause. Ron N
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