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.