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 (whether or not they actually occupy the choir) and the second to groups that perform in theatres or concert halls, but this distinction is far from rigid.
It should be noted that within choral music singers' voices are divided solely on the basis of vocal range. Choral music most commonly divides vocal parts into high and low voices within each sex. However, most music systems acknowledge seven different major voice categories. Women are typically divided into three groups: soprano, mezzo-soprano and contralto. Men are usually divided into four groups: counter-tenor, tenor, baritone and bass..
When considering voices of pre-pubescent children an eighth term, treble, can be applied. Within each of these major categories there are several sub-categories that identify specific vocal qualities like coloratura facility and vocal weight to differentiate between voices.
