PRs climbing sharper

[Tvak@aol.com]

Here is something I've never seen mentioned in books or on the list but is a 
consistent phenomenon to my experience.  When I return to a piano which had a 
big pitch raise, I find that the piano is sharper than where I left it.  For 
instance, yesterday, I returned to a piano that I raised 6 months ago from 
100 cents flat to A438 and found it at A440.  You could explain that by 
factoring in the summer humidity in this case, but I find this to be true no 
matter what time of year.  Tune it in the fall, come back in the spring 
before the windows open up and it's still sharper than where it was tuned to. 
 This phenomenon is so consistent that I now tune really flat pianos to A438. 
 Otherwise, I play tag with A440 and have to lower the pitch on my return 
visit.

This only happens after big pitch raises, of 35 cents or more.  I use RCT to 
pitch raise; whether it takes two passes or one, either way, my last pass is 
on a piano that is very close to the target pitch level.  

Comments?

Tom Sivak