Antiphony (Gr. response), the response which, in the Roman Catholic service, one side of the choir makes to the other in the chant. Antiphonal or responsive singing is the most ancient form of church music, and is said by the historian Socrates to have been first introduced among the Greeks by Ignatius, and among the Latins by St. Ambrose. The chanting of the psalms alternately is doubtless older than Christianity, and prevailed in the temple service of the Jews, many of the psalms being composed in alternate verses as if with a view to this mode of singing. In the cathedral worship of the Catholic church, two full choirs are stationed one on each side of the sanctuarv, one of which, having chanted a verse, remains silent, while the opposite choir replies in the verse succeeding; and at the end of each psalm the Gloria Patri is sung by the united choirs in chorus.