duet vs musical composition

duet and musical composition both are nouns.

Word	Noun	Adjective	Verb	Adverb
duet	Yes	No	No	No
musical composition	Yes	No	No	No

As nouns, musical composition is a hypernym of duet; that is, musical composition is a word with a broader meaning than duet:

Other hypernyms of duet include composition, opus, piece, piece of music.

duet (noun)	musical composition (noun)
(ballet) a dance for two people (usually a ballerina and a danseur noble)	a musical work that has been created
a musical composition for two performers
a pair who associate with one another
two performers or singers who perform together
two items of the same kind