sextet vs gathering

sextet and gathering both are nouns.

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

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

Other hypernyms of sextet include assemblage.

sextet (noun)	gathering (noun)
a musical composition written for six performers	the social act of assembling
six people considered as a unit	the act of gathering something
a set of six similar things considered as a unit	sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching
six performers or singers who perform together	a group of persons together in one place
the cardinal number that is the sum of five and one