in christian liturgy, an antiphon is the name of a short section, between the cleric, and usually the crowd. these sections are either spoken (the priest asks something, and the crowd gives a predefined answer, also spoken), or they are sung. when they are sung, the often use simple melodies. antiphons are very old: in the 4th century they were used in what is called ambrosian chant today. in liturgy, antiphons are not used on their own: the priest or person of the clergy says or chants these, while performing a ritual. in many pieces of church music, the choir (who replaces the crowd) starts singing as a response to an antiphon.