At times a choir may sing to or for a congregation of worshipers, but God remains the ultimate audience. However, a presentation from a choir can qualify as Christian proclamation every bit as much as a sermon. Intended as a gift to God, such a musical declaration is directed to members of the worshiping body.

Also, a worship service can be enhanced by including a piece of music that most of the worshipers cannot sing. In that situation, the choir sings for the congregation. Members of the choir present a musical gift to God on behalf of all who are present.

When a choir fulfills this function in worship, a congregation benefits from being able to read the words which are being sung.

from The Gift of Worship