composition vs quartet

composition and quartet both are nouns.

Word	Noun	Adjective	Verb	Adverb
composition	Yes	No	No	No
quartet	Yes	No	No	No

As nouns, quartet is a hyponym of composition; that is, quartet is a word with a more specific, narrower meaning than composition:

composition (noun)	quartet (noun)
the act of creating written works	a musical composition for four performers
musical creation	four people considered as a unit
something that is created by arranging several things to form a unified whole	a set of four similar things considered as a unit
the way in which someone or something is composed	four performers or singers who perform together
the spatial property resulting from the arrangement of parts in relation to each other and to the whole	the cardinal number that is the sum of three and one
an essay (especially one written as an assignment)
a musical work that has been created
art and technique of printing with movable type
a mixture of ingredients