This article is about the musical term. See Antiphon (person) for an article about an orator of ancient Greece.

The word Antiphon is of Greek origin, αντί(opposite) + φωνη(sound).

An antiphon is a response, usually sung in Gregorian chant, to a psalm or some other part of a religious service, such as at Vespers or at a Mass. This meaning gave rise to the antiphony style of singing, see call and response.

A piece of music which is performed by two semi-independent choirs interacting with one another, often singing alternate musical phrases, is known as antiphonal. In particular, antiphonal psalmody is the singing or musical playing of psalms by alternating groups of performers. This is particularly common in the Anglican musical tradition, where the choir divides into two equal halves on opposite sides of the quire. The Indian concept sawal-jawab ("question" and "answer") can be considered antiphonal. The alteration of individual notes or pitches is hocket.

Antiphon can also be used outside of a strict musical or liturgical context to mean a more general response. When used in this way the word often maintains its religious connotation.

When two or more groups of singers sing in alternation the style of music can also be called polychoral. Specifically, this term is usually applied to music of the late Renaissance and early Baroque. Polychoral techniques are a definitive characteristic of the music of the Venetian school, and this music is often known as the Venetian polychoral style. The Venetian polychoral style was an important innovation of the late Renaissance, and this style, with its variations as it spread across Europe after 1600, helps to define the beginning of the Baroque era. Polychoral music was not limited to Italy in the Renaissance; it was popular in Spain and Germany, and there are examples from the 19th and 20th centuries, from composers as diverse as Hector Berlioz, Igor Stravinsky and Karlheinz Stockhausen.