Flat Facts

[Ron Nossaman]

> Customer asked: "I understand that humidity change is the principle 
> cause for going out of tune, but if it gets flat than sharp, etc., why 
> is the long term trend always flat? In other words, if it's a fact that 
> the tuning pins are slowly turning counterclockwise with playing and 
> weather, why can't you just lock them in place, somehow, so the piano 
> stays close to pitch all the time?"
>  
> I stood there staring stupidly and could not conjur a 
> sensible-sounding answer.
>  
> What would YOU say?

With every cycle, bridge caps crush, bridge pins migrate, 
soundboards with high panel compression flatten, tuning pins migrate 
in the block. None of these tends to raise pitch in the long run. 
The universal assumption is that the tuning pins are turning 
backward, which seems unlikely to me, but none of the affects of 
cyclic pressures on wooden parts are considered.

That's what I'd say.
Ron N