quar·tet also quar·tette 
(kwôr-tĕt)
(kwôr-tĕt)n.
1. Music
a. A composition for four voices or four instruments.
b. A group of four singers or four instrumentalists.
2. A group of four.
[French quartette, from Italian quartetto, diminutive of quarto, fourth, from Latin quārtus; see QUART.]