Old Roman chant is the liturgical plainchant repertory of the Roman rite of the Early Christian Church formerly performed in Rome, closely related to but distinct from the Gregorian chant, which gradually supplanted it between the 11th century and the 13th century AD. Unlike other chant traditions such as Ambrosian chant, Mozarabic chant, and Gallican chant, Old Roman chant and Gregorian chant share essentially the same liturgy and the same texts, and many of their melodies are closely related. Although primarily associated with the churches of Rome, Old Roman chant was also performed in parts of central Italy and possibly even in Great Britain and Ireland.