ethnic music vs folk

ethnic music and folk both are nouns.

Word	Noun	Adjective	Verb	Adverb
ethnic music	Yes	No	No	No
folk	Yes	No	No	No

As nouns, ethnic music and folk are synonyms defined as:

ethnic music and folk: the traditional and typically anonymous music that is an expression of the life of people in a community

Other synonyms of ethnic music include folk music.

ethnic music (noun)	folk (noun)
the traditional and typically anonymous music that is an expression of the life of people in a community	the traditional and typically anonymous music that is an expression of the life of people in a community
	people in general (often used in the plural)
	a social division of (usually preliterate) people
	people descended from a common ancestor