The alternate singing or chanting by two sides of the choir and congregation, each taking a verse in turn. This mode of rendering the music of the Church is of very ancient origin; it prevailed in the ancient Jewish worship as the antiphonal structure of the Psalms indicates. It is a reproduction of the heavenly worship as described by Isaiah, "And one cried unto another and said." It seems to be also a practical following out of the admonition, "teaching and admonishing one another in psalms and hymns and spiritual songs." (Col. 3:16.)