Bill Ballard, and List - I think the kinds of changes you describe (piano's being heated, and possibly dried a little for a day or two) will not be significantly stressful in the _long term_ . If humidification is provided along with the heat, the structural stresses will be small and will take many days to reach new equilibria - and before then, the piano will be returned to it's 'unassisted' state. In the _short term_ however, you can expect the tuning to be somewhat unstable. I have had two relevant experiences, one exactly as the situation you describe: S&S 'D' , tuned and used lots during the summer, outdoor environment (except with a roof over its head), hall heated for an occassional performance during fall and spring. The piano behaves beautifully all summer with nary a pitch-raising. When the heat comes on (for one day only, no humidification) there can be a six- to eight- cent pitch drop, depending on the weather. Since this is a very sophisticated venue presenting international concert pianists, we go through the pitch-raising, plus a touch-up tuning just before performance. If the piano is used another time or two (with temporary heat) during the same off-season, the piano doesn't usually require another pitch-change. But it does need pitch-lowering again for the start of the summer season with its high humidity. As for temperature change, it will affect the tuning, and sometimes dramatically and quickly. I'd like to see the piano have about an hour to settle for each three-degrees Fahrenheit of temperature change. (Nothing scientific to prove that, just an experienced rule of thumb.) With that in mind you can specifiy the minimum lead time for the heat to be brought up to battle conditions before you attempt a fancy tuning. Situation #2: Beautiful concert hall with an S&S 'D', wonderfully climate-controlled storage room, but no humidification in the hall. Temperature changes were negligible, and _sometimes_ humidity changes were negligible, too - heavenly days! But at other times, the piano could go from 45% RH in storage to 15% ambient condition on stage. The tuning would be constantly descending throughout the day of performance, and through the performance. My typical regimen was to schedule the piano brought on stage early in the morning (the day before - or week before, a la Ken Sloane's experience! - was never a possibility due to the other uses of that hall), tune before afternoon rehearsal with an attempt to anticipate the pitch level at performance time, then touch-up just before the doors open, with no further pitch-changes, even if needed. (In other words, working for stability instead of pitch accuracy for this touch-up). This worked beautifully for solo recitals, and pretty well for concertos. I had to explain the situation to the orchestra (i.e., the Oboist) and the conductor. Both were appreciative of my attentions and ultimately understanding of the circumstances. (Like Ken, I had doubts that this was a good situation for the piano. But the auditorium manager and staff were so proud of the system...! BTW, once I got this regimen adopted, I stuck with it even if the weather was doing us a favor and not dealing us a pitch-change. I could always use the time for some additional tweaking and regulating. The artists loved this, and in general, the piano was very well maintained and it served many wonderful concerts. Good luck, Bill! - Tom McNeil, RPT - Vermont PIano Restorations P.S. Remember, when large capital projects are afoot (like building or renovating a concert hall) that's the time to budget for a new piano. The present one can serve as #2, or as a back-up, etc.
This PTG archive page provided courtesy of Moy Piano Service, LLC