An antiphon ( Greek ἀντίφωνον, ἀντί "opposite" and φωνή "voice") is a short chant sung as a refrain . The texts of antiphons are the Psalms . Their form was favored by St Ambrose and they feature prominently in Ambrosian chant , but they are used 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 . When a chant consists of alternating verses (usually sung by a cantor) and responses (usually sung by the congregation), a refrain is ON THE PENTAD 73 and the animal under the hexad then the vegetative necessarily falls under the pentad with the result that the pentad...