Antiphon

A Catholic liturgical chant with a prose text associated with psalmody sung by two choirs in alternation, often part of roman catholic and Greek orthodox church services. may be sung as responses between a single voice and a group of voices, or between two different groups of singers. the effect of this back-and-forth is described as antiphonal. It is usually a response or refrain to a psalm or canticle verses. The response made by one part of the choir to another, or one by the congregation to the priest in a Catholic service; also, alternate singing.A musically interesting section of chant which is sung by a choir; the text and music were intended to serve as a frame to a psalm verse (or a series of psalm verses), introducing and following it. The term is used sometimes to mean sacred song (e.g. Marian antiphons).