Would a piano be classified as a string instrument or a percussion?

[tripalreno4]

According to my understanding, a typical grand piano essentially works by vibrating strings. However, I have heard various people, as well as an academic argue that pianos are essentially percussion instruments?

[outin]

According to my understanding, a typical grand piano essentially works by vibrating strings. However, I have heard various people, as well as an academic argue that pianos are essentially percussion instruments?

They are, because the strings are hit by a hammer and the sounds starts to decay after that. The original attack is what the player can control. The sound is by default percussive even if we try to pretend it is not. "Proper" string instruments when played with a bow have a sound that is continuing and under control of the player as long as it sounds.

[j_tour]

You know, this thread crossed my "mind" or what exists of it recently.

Yes, by definition, and by any reasonable account, obviously.  It's not just the method of approaching the keyboard, but also the simple physical aspects.

But, what led me to consider replying was listening to some work on guitar, especially using the slide (you know, whether it's a Coricidin bottle or a brass slide or just a butter knife or whatever:  not exactly classical guitar technique, but anyone who's played a bit knows what I mean).

So, riddle me this, then:  as we know, on the guitar, much like on the piano, the string is plucked.  Much like on a harpisichord.  In fact, in some dialects of English, this is accomplished using the "plectrum," or equally, a "pick."  Or, perhaps just one's finger (lets not complicate it too much).

I think the distinction is really to be made between stringed instruments which are played arco, or those which primarily depend on the initial attack (and decay) for the meat of the sound.

I'm not sure that the distinction of percussive or string is relevant, and I'd rather say that an emendation to the terminology is what's called for.

[outin]

I think usually "string instruments" refer to the one's that are played with a bow. A guitar is also an instrument with strings ie a stringed instrument. The problem here is that in English the concepts in everyday language are not clear and the more scientific classification is not very handy: Idiophones, membranophones, chordophones, aerophones and electrophones.

This is a non issue in my language, since we actually do not talk about string instruments when referring to violin, cello etc., instead we say "bow instruments". "String instruments" refer to all sorts of things, guitar, harp, banjo.
Piano, harpsichord, organ etc are referred as "key instruments". So the words used for classification are based on the method of playing more than the actual existence of strings or not.

[klavieronin]

In Walter Piston's book on orchestration he classifies the piano as a "Keyboard" instrument, which was my understanding also.