The ward choir is a necessary part of the Church program, and every ward should have an active choir. The bishopric may invite or call ward members to participate in the choir. . . .
It is recommended that ward choirs sing in at least two sacrament meetings each month throughout the year.An important function of choirs is to strengthen and support the singing of Church members. During congregational hymns, Church members who are less confident in their singing abilities can follow the lead of choir members.
Choirs can be used to help members become more familiar with the hymns and introduce them to lesser-known hymns. Occasionally the congregation may be invited to join the choir on selected verses of a hymn.
- Church Music Handbook, p. 6