noun
instrumental quartet
Refers to a musical ensemble of four instruments or a composition for such an ensemble. Often used in classical music contexts.
弦楽四重奏の演奏会に行った。
I went to a string quartet concert.
四重唱 refers to a vocal quartet (four singers), while 四重奏 is specifically for instrumental quartets.
Compound of 四 (four), 重 (layer, fold), and 奏 (play music). The term follows the pattern of other ensemble words like 二重奏 (duet) and 三重奏 (trio).