rumba vs dance music

rumba and dance music both are nouns.

Word	Noun	Adjective	Verb	Adverb
rumba	Yes	No	Yes	No
dance music	Yes	No	No	No

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

rumba (noun)	dance music (noun)
a folk dance in duple time that originated in Cuba with Spanish and African elements; features complex footwork and violent movement	music to dance to
a ballroom dance based on the Cuban folk dance	a genre of popular music composed for ballroom dancing
syncopated music in duple time for dancing the rumba

rumba (verb)	dance music (verb)
dance the rhumba