Antiphonal singing

An antiphon (Greek ἀντίφωνον, ἀντί "opposite" and φωνή "voice") is a short chant in Christian ritual, sung as a refrain. Antiphons are Psalm-texted. Their form was favored by St Ambrose and so they feature prominently in Ambrosian chant, but they occur widely in Gregorian chant as well. They may be used during Mass, for the Introit, the Offertory or the Communion. They may also be used in the Liturgy of the Hours, typically for Lauds or Vespers.

They should not be confused with Marian antiphons or processional antiphons.

A refrain is needed when a chant consists of alternating verses (usually sung by a cantor) and responds (usually sung by the congregation).

The looser term antiphony is generally used for any call and response style of singing, such as the kirtan or the sea shanty. Antiphonal music is that performed by two choirs in interaction, often singing alternate musical phrases.Antiphonal psalmody is the singing or musical playing of psalms by alternating groups of performers. The term “antiphony” can also refer to a choir-book containing antiphons.

The 'mirror' structure of Hebrew psalms renders it probable that the antiphonal method was present in the services of the ancient Israelites. According to the historian Socrates of Constantinople, antiphony was introduced into Christian worship by Ignatius of Antioch (died 107), who saw a vision of two choirs of angels.

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