brass v. iron

[Roger Jolly]

>So I would disagree that humidity is *not* a factor. I would also disagree
>with Roger how ever. You can give repeateable phenomina predict what the
>wood will do. (Atleast to the tuning).

Hi Don,
             I would sure like to know the coefficient of linear expansion
per degree for Sitka Spruce? IS there a coefficent of expansion for each
percentage point of RH at a fixed temperature? NO. We get to know the
personality of certain pianos that we very frequently work on, but the
point I was making is that you can not calculate in cents the change due to
humidity and temp. You have two D's at the Centre, do they react exactly
the same? Maybe be some what similar, but not identical.
Regards Roger 

Roger Jolly
Baldwin Yamaha Piano Centre
Saskatoon and Regina
Saskatchewan, Canada.
306-665-0213
Fax 652-0505