singing vs Greek chorus

singing and Greek chorus both are nouns.

Word	Noun	Adjective	Verb	Adverb
singing	Yes	Yes	No	No
Greek chorus	Yes	No	No	No

singing (noun)	Greek chorus (noun)
the act of singing vocal music	a company of actors who comment (by speaking or singing in unison) on the action in a classical Greek play
disclosing information or giving evidence about another

singing (adjective)	Greek chorus (adjective)
smooth and flowing