quintet vs piece of music

quintet and piece of music both are nouns.

Word	Noun	Adjective	Verb	Adverb
quintet	Yes	No	No	No
piece of music	Yes	No	No	No

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

Other hypernyms of quintet include composition, musical composition, opus, piece.

quintet (noun)	piece of music (noun)
a musical composition for five performers	a musical work that has been created
five people considered as a unit
a set of five similar things considered as a unit
five performers or singers who perform together
the cardinal number that is the sum of four and one