I've been wondering about this since 4th grade ...

and I think I figured it out yesterday while watching the Guy Lombardo Show on PBS ... (yes, I enjoy watching that and the Lawrence Welk Show as well ... there is humor, it is wholesome, and I like it).

Now, don't misunderstand me ... it is not as though I have been in deep continuous cogitation on this matter since elementary school ... but, I remember learning that the piano was part of the percussion family and that did not make sense to me until last night while I watched a performer play the harp with quite masterful speed and precision. As he played I noticed the similarity in sound between the music advancing and the sound of a piano ... but I was certain a harp is part of the string family, and, as already mentioned, I recalled that a piano is part of the percussion lineage.

So as I sat and watched I pondered what is the difference between the two instruments and how they are played, even though they are capable of producing similar sounds in the right hands?

What makes one a string and one a percussion?

I noted that the harp sounds are the result of the hands pulling or plucking on the strings, while the sounds of a piano result from the pushing or pounding of the hands on keys that result in a hammer striking the strings ... this pushing motion reminded me of the motions needed to elicit the sounds of other percussion instruments, like drums.

I concluded, therefore that this is why the piano is a percussion instrument, because of the percussing action that results in a sound.

When I "googled" it, I found out I had reasoned through to a correct conclusion.

Now, it is true I might have easily looked this up some time ago, but it was more fun this way!