BKN1964 What about a "toy" piano where the hammers strike chimes or a xylophone? Is that still a piano?
Yes it is - a piano - if there is 'adequate' and independent soft-loud control of the notes of the instrument -- and I quote adequate because some say that if it does not get 'adequately' loud (as some say for the case of clavichord), then it's not a piano. But I also did mention in the thread that I'm happy to have the toy pianos etc welcomed into the piano family. If you can get 'adequate' piano forte - then it's a piano. I'm fine with it even if you can't get it loud enough - as you could always add a mic/transducer etc - and get it real loud. But once again - it goes back to piano forte, which does relate to dynamic range (and some people say - even absolute audio power/volume levels to some extent). And 'adequate' is subjective. But we get the picture in general.
I had it all covered before - here and in my other lectures on this subject. If it has adequate soft-loud control of the independent notes (pitch set) - and you can control it by pushing the keys, and importantly it is workable for musical application(s) - then it's a piano. Piano forte - the essence is what it is all about. You, one could also say that you don't always necessarily need to use it for musical applications though, which is sometimes we can just write - in 'general' (mentioned before/above already).
And - obviously - if one wants a piano that has adequate substance in sound - some 'oomph' etc in the sounds - then sure, we have pianos (in the digital and acoustic categories) for handling that --- the ones we know a lot, ie. the sound of 'struck strings' of a harp structure enclosed in a cabinet or semi-enclosed cabinet. Sympathetic resonance - which is often very nice too - often making the piano music sound good/rich/interesting - with adequate substance etc.
BKN1964 What if it's a piano in the traditional sense, except that the hammers are actuated by a computer, or something like electro-mechanical means instead of pure mechanical?
If the generally-agreed-upon condition is that it is playable by pushing levers or keys etc with piano forte, then we have a piano. But if you remove the 'keyboard' levers etc for playing it ... then it's not a piano.
Everybody usually agrees that a piano does have the keyboard/keys. If you remove the 'keys' components, then you can't use your body to get the piano forte happening.
The idea is/was to have polyphonic piano forte music instrument for a person to play. This was the idea or goal back in the 'old' days. A piano could probably play itself back then too ... but that is getting into an area where we have to keep the lights on at night (and garlic etc) for a week or so ... just to be on the safe side. Probably a good idea to leave the lights on during the day too.
