Pianos as Percussion

One of the pianists who objected to a piano being called a percussion
instrument cited a book called the Ultimate Encyclopedia of Musical
Instruments, which said that, in summary, whether an instrument has strings
is a more basic consideration than whether it produces sound by percussion.

That strikes me as a reasonable claim. I'm not sure if I agree that
either is clearly more important a distinction than the other, but if there
is indeed a precedent for strings-or-not being a more basic distinction,
then I'll play along.

Until this though, I would have classified piano, along with guitar,
clavichord, harpsichord, mandolin, lute, etc., as both percussion and
stringed instruments. If it produces sound by applying a burst of energy
to vibrating medium, and then lets it die away, I would have called it
percussion.

That then raises an interesting question: Is there a word for such an
instrument? Perhaps "percussive" instead of "percussion"?

I'd rather classify the instruments by the direct, primary means of playing
the instrument: bowing, plucking, keying, striking (Russolo's classes can be
applicable).

Clavichords, harpsicords and pianos share the initial actuating lever of a
keystick, and while the posture and playing style are similar enough to
constitute a class, ultimately they do not share mechanics. The tangential key
of the clavichord does not work in the same sense as a mallet, nor does the
hinged tongue of a harpsichord work like escapement does in a piano action.

The Turkish music piano of the early 19th century sometimes featured a
pedal mallet that struck the less-strung, more membranous soundboard directly,
but this is more akin to bowing cymbals.

In my opinion, the distinctness of the piano (fretted clavichord,
harpsichord, harp, chittarone/theorbo and baryton) lies less in the strings
than in their number.

Clark