black music vs music genre

black music and music genre both are nouns.

Word	Noun	Adjective	Verb	Adverb
black music	Yes	No	No	No
music genre	Yes	No	No	No

As nouns, music genre is a hypernym of black music; that is, music genre is a word with a broader meaning than black music:

black music: music created by African-American musicians; early forms were songs that had a melodic line and a strong rhythmic beat with repeated choruses
music genre: an expressive style of music

Other hypernyms of black music include musical genre, musical style.

black music (noun)	music genre (noun)
music created by African-American musicians; early forms were songs that had a melodic line and a strong rhythmic beat with repeated choruses	an expressive style of music