Term used for the monophonic liturgical repertoire of the Catholic church. Used interchangably with chant, plainsong, and Gregorian chant. Plainchant originated in Jewish and pagan ritual music around the early Christian centers, then developed in regional families for seven centuries. In the eighth century, as part of Charlemagne's unification of Christian Europe, the regional familes were supressed in favor of an official uniform Gregorian chant.

Monophonic music used in Christian liturgical services. It is sung in unison and in a free rhythm, and as a style probably dates from the first century of the Christian era.

See chant.