A choir (/kwaɪər/ KWIRE), also known as a chorale or chorus (from Latin chorus, meaning 'a dance in a circle'), is a musical ensemble of singers. Choral music, in turn, is the music written specifically for such an ensemble to perform or in other words is the music performed by the ensemble. Choirs may perform music from the classical music repertoire, which spans from the medieval era to the present, or popular music repertoire. Most choirs are led by a conductor, who leads the performances with arm, hand, and facial gestures.
The term choir is very often applied to groups affiliated with a church (whether or not they actually occupy the quire), whereas a chorus performs in theatres or concert halls, but this distinction is not rigid. Choirs may sing without instruments, or accompanied by a piano, accordion, pipe organ, a small ensemble, or an orchestra.