My late mentor did some measuring. S&S D tuned to 441hz at A4 under a single light was just under 440 hz under full stage lighting. I'd have to dig in the archives but he had a Fahrenheit to cents ratio with in normal tuning tensions. Probably why Steinway literature recommends tuning the D to 441. Andrew Anderson At 09:26 PM 2/10/2007, you wrote: >Regarding primarily large concert pianos, does >anyone have data on how much the pitch changes with temperature fluctuations? > >This is a question I'll no doubt answer in time >as I get more experience servicing concert >grands. But I regularly service only one >Steinway D, and I haven't worked with it long >enough to know how it reacts to temperature >changes. It has a DC system, though, which keeps >it very close - as long as it's plugged in and in its storage area. > >Scenario: >Yesterday, piano was -2¢, so it was tuned to >A440 in one pass since I was coming back today >to check it again. Temp was 67.6°F, and RH was 26%. > >Today, piano was about 3-4¢ flat (a little more >in low tenor). Temp was 72.9°, with the humidity >at 25%. So I'm seeing the most likely cause of >the change in pitch is the thermostat (and body >heat from the orchestra as well). OK, I think I >understand all the whys behind the changes, but >I had no idea that 5° would make that much >difference. After talking with a piano tech >friend of mine who routinely takes care of >several D's, he confirmed that these pianos are >indeed that sensitive to the temp change. > >For future reference, does anyone have data on >how much change happens with temperature >fluctuations like this? I could say, based on my >first non-scientific collection of observation >data, that it changes about 3-4¢ for every 5° of >temperature increase. <g> Is that about right generally? > >What do you guys do? Do you not worry about >where the temperature is? If you think it will >be different at performance time, do you set the >pitch accordingly, and hope it changes in your >favor? Or do you simply tune it to A440 and don't worry about it? > >Another thing that's frustrating is that I tuned >it yesterday with the stage lights on, so as to >minimize the pitch change that comes from >lights. But today, it was back in the little >storage room and the stage is set up for the >orchestra. Apparently, the piano is coming out >after intermission. ?? I didn't look at a >program, so I dunno. But anyway, it kind of >stinks because today the unisons were all wobbly >anyway - no telling what happened when the >lights hit it tonight. Oh well, at least I have >one thing in my favor: most people aren't as >sensitive to pitch as tuners are, so I'm sure >I'm overreacting to what was probably a very >minor issue, if noticed at all. <g> > >Thanks for any help with this. > >JF
This PTG archive page provided courtesy of Moy Piano Service, LLC