quartet vs musical organisation

quartet and musical organisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
quartet	Yes	No	No	No
musical organisation	Yes	No	No	No

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

Other hypernyms of quartet include musical group, musical organization.

quartet (noun)	musical organisation (noun)
a musical composition for four performers	an organization of musicians who perform together
four people considered as a unit
a set of four similar things considered as a unit
four performers or singers who perform together
the cardinal number that is the sum of three and one