Definitions for quartette
four performers or singers who perform together
quartet, quartette, quadruplet, quadruple(noun)
a set of four similar things considered as a unit
quartet, quartette, foursome(noun)
four people considered as a unit
"he joined a barbershop quartet"; "the foursome teed off before 9 a.m."
a musical composition for four performers
a composition in four parts, each performed by a single voice or instrument
the set of four person who perform a piece of music in four parts
a stanza of four lines
The Nuttall Encyclopedia
a musical piece in four parts, or for four voices or instruments.