Assertion: electronic piano | /r/HasProperty | connected to a keyboard amplifier
Facets:
value: to produce sound
type: PURPOSE
Source sentences:
text: They must be connected to a keyboard amplifier and speaker to produce sound (however, some electronic keyboards have a built-in amp and speaker).
text: They must be connected to a keyboard amplifier and speaker to produce sound (however, some electronic keyboards have a built-in amp and speaker).