folk singer vs vocalizer

folk singer and vocalizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
folk singer	Yes	No	No	No
vocalizer	Yes	No	No	No

As nouns, vocalizer is a hypernym of folk singer; that is, vocalizer is a word with a broader meaning than folk singer:

Other hypernyms of folk singer include singer, vocaliser, vocalist.

folk singer (noun)	vocalizer (noun)
a singer of folk songs	a person who sings
	an organism that can utter vocal sounds