Architecturally, the choir (Anglican alt. spelling quire) is the area of a church or cathedral, usually in the western part of the chancel between the nave and the sanctuary (which houses the altar). The choir is occasionally located in the eastern part of the nave. In some monastic churches the choir occupies the western end of the nave and thus counterbalances the chancel and sanctuary.
In the Early Church the sanctuary was connected directly to the nave. Choir was simply the east part of the nave, and was fenced off by low railing, called cancelli, from which we get our English word chancel. The development of the architectural feature known as the choir is the result of the liturgical development brought about by the end of persecutions under Constantine the Great and the rise of monasticism. The word "choir" is first used by writers of the Western Church. Isidore of Seville and Honorius of Autun write that the term is derived from the "corona", the circle of clergy or singers who surrounded the altar.
When first introduced, the choir was attached to the bema, the elevated platform in the center of the nave on which were placed seats for the higher clergy and a lectern for scripture readings. This arrangement can still be observed at the Basilica of St. Mary Major in Rome. Over time, the bema (or presbytery) and choir moved eastward to their current position. In some churches the choir is arranged in the apse behind the altar.
The pulpit and lectern are also particular to this area of the church. There may also be another free-standing lectern in the center of the isle, facing towards the sanctuary. The organ may be located here, or in a loft elsewhere in the church.
The choir area is occupied by sometimes finely carved and decorated wooden seats known as choir stalls, where the clergy sit, stand or kneel during services. The choir may be furnished either with long benches (pews) or individual choir stalls. There may be several rows of seating running parallel to the walls of the church.
The use of choir stalls (as opposed to benches) is more traditional in monasteries and collegiate churches. Monastic choir stalls are often fitted with seats that fold up when the monastics stand and fold down when they sit. Often the hinged seat will have a misericord (small wooden seat) on the underside on which he can lean while standing during the long services. The upper part of the monk's stall is so shaped as to provide a headrest while sitting, and arm rests when standing. Monasteries will often have strict rules as to when the monastics may sit and when they must stand during the services.
Choir benches are more common in parish churches. Each bench may have padded kneelers attached to the back of it so that the person behind may kneel at the appropriate times during services. The front row will often have a long prie-dieu running in front of it for the choir members to place their books on, and which may also be fitted with kneelers.
See also 
|Wikimedia Commons has media related to: choirs (architecture)|
- "Choir" article from The Catholic Encyclopedia
- "Stalls" article from The Catholic Encyclopedia
- Choir and Retro-Choir at Southwark Cathedral