Assertion: bass trombone | /r/HasAspect | two valves
Facets:
value: typically
type: DEGREE
Source sentences:
text: The modern bass trombone is the same length as a tenor trombone, but typically has two valves, one pitched in F and one in G♭.
text: Modern bass trombones also have one or two valves (the latter being by far the more common) which, when engaged, change the key of the instrument.
text: Although principally pitched to B-flat, bass trombones have either one or two valves that allow you to play in F and/or G.