Effect of pitch raise 440-443 and back

[Maxpiano@AOL.COM]

List-

A venue I tune for is having the Czech Philharmonic in February with the 
requirement the piano be tuned to A=443.  

My concern is not how to do and undo the pitch raise.  I've already discussed 
the extra costs with the management, including letting it down afterward.

The piano has the clearest tone of any I service, hardly a sign of false 
beats until one gets into the top octave.  It's a Yamaha CFIII (the little 
plate on the stretcher indicates Yamaha Concert Reserve and the story bandied 
about is that it was used by Andre Watt and was originally a $110,000 
instrument.  I've wondered if it should have the "S" designation).  

Can raising and lowering be expected to introduce false beats (from moving 
the bends into the speaking length of strings)?  

I'll appreciate any advice.

Bill Maxim, RPT
Simpsonville, SC