Antiphon
From Conservapedia
An antiphon is a liturgical chant, historically used during Roman Catholic and Orthodox ritual, sung by two choirs alternatively, in a verse and response style, using generally simple chant melodies to biblical sentences. It was sung between verses of the psalms at various times during the service, and developed to include antiphonal processional chants and texts in praise of Mary. Rhyming texts appeared during the 13th century. It was particularly popular in the English church before and during the Reformation and was a prime ingredient in the formation of the English anthem.
The term (Latin: antiphona) is of Greek origin and first appeared in Western Europe during the 4th century.[1]