1811, "composition for five voices," from Italian quintetto, diminutive of quinto "fifth," from Latin quintus "the fifth," related to quinque "five" (from PIE root *penkwe- "five"). Meaning "set of five singers or players" is from 1882.
quinta
quintain
quintal
quintessence
quintessential
quintet
quintile
quintillion
quintuple
quintuplet
quinzane