I wish to raise a point...

[Paul N. Bailey]

What about pianos that were designed and built for a lower pitch level, 
like 435 or 436?

Recently I appraised a Kohler and Chase ur. that had "C 517" painted on the
plate, near the serial number. I think they meant that piano to be at A
435.
Curious, that the pitch level was expressed as a "C" and not an "A".

I often tune old uprights at 435 or 436 if I have reason to think that was
the intention of the builder. I tell the client, and if they are going to 
be playing with modern wind instruments, I might try to nurse it up to 438.
If they're happy to pay me to replace broken wires, well....

I think pianos designed for 435 sound better at that pitch. Also, I've met
lots of old pianos that had been brought to the 440 level in the midrange,
but the high treble was still about 20 cents low - however that happened.
Some of these old pianos seem to be better sounding and more stable at the
"old" pitch. 

I wonder if a poor sounding and unstable tuning at modern pitch is better 
than a good sounding and stable tuning at 435?

Not to disagree with any other expressions in this thread - these questions
are always judgment calls in each situation, and I agree about the
importance
of standard pitch.

                        Paul Bailey