noun
vocal duet
A musical piece for two singers, or the performance of such a piece. Compare with 二重奏 (instrumental duet).
彼らは結婚式で美しい二重唱を披露した。
They performed a beautiful vocal duet at the wedding.
デュエット is a more general loanword for duet, used for both vocal and instrumental duets, and is more casual.
Compound of 二重 (double, two-fold) and 唱 (singing, chant).