diaglo said:
are they talking piano or dulcimer? or pipe organ? or xylophone?
many if not all of these are already included in other instrument categories.
While piano is a percussion instrument, it doesn't make much sense to lump the ability to play drums together with the ability to play piano.
Likewise, pipe organ is a wind instrument, but it is played by a keyboard, and the ability to play organ is more closely related to the ability to play another keyboard instrument [such as piano] than the ability to play, say, flute or trumpet.
A dulcimer, as far as I know, is a stringed instrument. Hammer dulcimers are played percussively...but I'm not aware of a keyboard dulcimer.
A xylophone can be laid out somewhat like a keyboard, but it's quite a stretch to consider it a keyboard instrument. It's percussion.
So keyboard instruments would include anything reasonably close to a piano --- pipe organs, piano accordions [and probably buttom accordions / concertinas, although the "keyboard" is different], melodicas, harpsichords, and Hammond B-3s.
[jpl just got a mandolin, and is considering quitting his day job and getting the band back together...]