Choirs are interesting.  They are also known as a quire, chorale, or chorus.
Are you talking about the groups with a large amount of people singing different tones and ranges to make a song?
Choir
A choir (; also known as a quire, chorale or chorus) 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
school's annual musical production and several smaller ensembles.
The choral program includes two all-female choirs known as Treble Choir and Women's Chorale, a mixed four-part choir called ChoralWorks, and an all-male choir known as Men's Chorus. Membership in ChoralWorks and Women's Chorale is determined by audition. The choirs generally have three concerts during the school year, with additional performances in and outside of school at various times of the year. There are also three additional extracurricular ensembles, two all-female