Assertion: piano's key | /r/HasProperty | hidden under small hinged lid
Facets:
value: sometimes
type: TEMPORAL
Source sentences:
text: These extra keys are sometimes hidden under a small hinged lid that can cover the keys to prevent visual disorientation for pianists unfamiliar with the extra keys, or the colours of the extra white keys are reversed (black instead of white).
text: These extra keys are sometimes hidden under a small hinged lid that can be flipped down to cover the keys in order to avoid visual disorientation in a pianist unfamiliar with the extended keyboard.
text: These extra keys are sometimes hidden under a small hinged lid that can cover the keys to prevent visual disorientation for pianists unfamiliar with the extra keys, or the colours of the extra white keys are reversed (black instead of white).