the answer made by one choir to another, when the psalm or anthem is sung between two.

Antiphony, sometimes denotes a species of psalmody, wherein the congregation, being divided into two parts, repeat the psalms, verse for verse, alternately. In this sense, antiphony stands contradistinguished from symphony, where the whole congregation sings together.

Antiphony differs from responsorium, because in this latter the verse is only spoken by one person, whereas in the former, the verses are sung by the two choirs alternately. The original of Antiphonal singing in the western churches is referred to the time of St Ambrose, about the year 374. That father is said to have first introduced it into the church of Milan, in imitation of the custom of the eastern church, where it appears to be of greater antiquity, though as to the time of its institution, authors are not agreed; it was most probably introduced at Antioch, between the year of Christ 347 and 356.

Antiphony is also used to denote the words given out at the beginning of the psalm, to which both the choirs are to accommodate their singing.

a more modern sense, denotes a kind of composition made of several verses extracted out of different psalms, adapted to express the mystery solemnized on the occasion.