Claim: Choir is also known as a chorus.

A choir -LRB- -LSB- ` kwaɪ.ər -RSB- -RRB- -LRB- also known as a chorale or chorus -RRB- is a musical ensemble of singers . Choral music , in turn , is the music written specifically for such an ensemble to perform . 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 and face gestures .   A body of singers who perform together as a group is called a choir or chorus . The former term is very often applied to groups affiliated with a church -LRB- whether or not they actually occupy the choir -RRB- and the second to groups that perform in theatres or concert halls , but this distinction is far from rigid . Choirs may sing without instrumental accompaniment , with the accompaniment of a piano or pipe organ , with a small ensemble -LRB- e.g. , harpsichord , cello and double bass for a Baroque era piece -RRB- , or with a full orchestra of 70 to 100 musicians .   The term `` Choir '' has the secondary definition of a subset of an ensemble ; thus one speaks of the `` woodwind choir '' of an orchestra , or different `` choirs '' of voices or instruments in a polychoral composition . In typical 18th - to 21st-century oratorios and masses , chorus or choir is usually understood to imply more than one singer per part , in contrast to the quartet of soloists also featured in these works .