Assertion: clarinet's instrument | /r/HasAspect | key
Facets:
Source sentences:
text: The earliest instruments were shaped like a walking stick with a mouthpiece in the handle and had no keys, although they could eventually have up to thirteen keys, along with a tuning slide and a device for narrowing the thumb hole.
text: In the 18th century, the instruments were made of wood or ivory and had three or four sections and two keys –
text: In this period, the instrument had six finger holes and single thumb hole, and had as many as six keys.