Assertion: concertina's button | /r/HasProperty | key
Facets:
value: in places
type: LOCATION
Source sentences:
text: The word concertina refers to a family of hand-held bellows-driven free reed instruments constructed according to various systems, which differ in terms of keyboard layout, and whether individual buttons (keys) produce the same (unisonoric) or different (bisonoric) notes with changes in the direction of air pressure.
text: It’s worth noting here that you may see buttons referred to as keys in places, try not to get confused!
text: It has 20 button keys – two rows of ten buttons on each of the right and left sides of the concertina.