dance band vs rock band

dance band and rock band both are nouns.

Word	Noun	Adjective	Verb	Adverb
dance band	Yes	No	No	No
rock band	Yes	No	No	No

As nouns, rock band is a hyponym of dance band; that is, rock band is a word with a more specific, narrower meaning than dance band:

Other hyponyms of dance band include big band, combo, jazz band, jazz group, rock group, steel band.

dance band (noun)	rock band (noun)
a group of musicians playing popular music for dancing	a band of musicians who play rock'n'roll music