quartette vs gathering

quartette and gathering both are nouns.

Word	Noun	Adjective	Verb	Adverb
quartette	Yes	No	No	No
gathering	Yes	No	No	No

As nouns, gathering is a hypernym of quartette; that is, gathering is a word with a broader meaning than quartette:

Other hypernyms of quartette include assemblage.

quartette (noun)	gathering (noun)
a musical composition for four performers	the social act of assembling
four people considered as a unit	the act of gathering something
a set of four similar things considered as a unit	sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching
four performers or singers who perform together	a group of persons together in one place