Front Rail Felt Theory

[Ron Nossaman]

> Is there any rhyme or reason for a billion
>different sizes? Or are different sizes made simply because the
>manufacturers can sell them. And folks that are bothered by these things sit
>in misery while they wonder in frustration: why?
>
>Terry Farrell

Oh, that's simple. Just look at all the different sizes of key bushing
cauls that are necessary to fit all the different sizes of key pins that
have been used in the last 150 years. There used to be a formula, seldom
acknowledged, involving the average of the diameters of the front and rear
pins (measured front to back and side to side to account for ovularity),
divided by the straight line distance of the tips of the pedals from the
key overhang (if there is one), times the standardized speaking length of
C-8. This figure is then multiplied by the logarithm of the ratio of
overall piano height, to overall length front to back (this is why you tend
to see larger diameter punchings in grands), and marinated in a highly
proprietary constant that curiously shrinks the punching dimension to fit
the requirements of the piano. How this constant was arrived at has never
been divulged, but it has been long suspected to involve certain species of
mushrooms. The present abundance of apparently arbitrary combinations of
diameters, thicknesses, densities, and colors, merely indicates the
continued reliance upon and availability of these mushrooms. That is also,
incidentally, why the punchings should be kept under the keys where it is
relatively dark, and protected by the layers of accumulated loam. 

I hope this is of some help.

Ron N