Nobody can hear fundamental musical pitches up to anywhere near
20,000 Hz, not even new-born babies with perfect ears. The upper
range of human hearing is only useful for hearing overtones and
harmonics that are basically "felt" rather than "heard". There
are a few notes above the range of the piano that can be heard,
but they are not musically useful. A very skilled violinist can
produce these using harmonics. You could produce these pitches
with some analog electronic synthesizers, but not with an
acoustic instrument. If you try this yourself, it will occur to
you that you've never heard these pitches used in any actual
music because they are not musically useful and because few
people can hear them, and those that can find them unpleasant to
listen to. Neil, piano design aside, there's a fundamental
misunderstanding in your line of questioning. You read in a book
somewhere that the range of human hearing goes up to 20,000 Hz.
Well, so what? That is only a theoretical construct. Different
individuals have d