singing vs revealing

singing and revealing both are nouns.

Word	Noun	Adjective	Verb	Adverb
singing	Yes	Yes	No	No
revealing	Yes	Yes	No	No

As nouns, revealing is a hypernym of singing; that is, revealing is a word with a broader meaning than singing:

Other hypernyms of singing include disclosure, revelation.

singing (noun)	revealing (noun)
the act of singing vocal music	the speech act of making something evident
disclosing information or giving evidence about another

singing (adjective)	revealing (adjective)
smooth and flowing	showing or making known
	disclosing unintentionally something concealed