Iégor Reznikoff

Gregorian chant is the central Western tradition of plainchant: a monophonic, unaccompanied sacred song in Latin (and occasionally Greek) used in the Roman Catholic liturgy. It employs free rhythm guided by the prosody of the text rather than by strict meter, and is sung in unison by clerics or scholas. Its melodies are organized by the system of eight church modes, with characteristic finalis (final), tenor/reciting tones, and melodic formulas. Repertoires include the Proper and Ordinary of the Mass (e.g., Introit, Gradual, Alleluia, Offertory, Communion, Kyrie, Gloria, Credo, Sanctus, Agnus Dei) and the Divine Office (e.g., Antiphons, Responsories, Hymns, Psalms). Although legend credits Pope Gregory I, modern scholarship sees Gregorian chant as a Carolingian synthesis of Old Roman and Gallican chants, standardized across Frankish realms and later the broader Latin West.

Gallican chant is the body of liturgical plainchant associated with the Gallican rite practiced in early medieval Gaul (roughly modern France and adjacent regions) before the Carolingian reforms. It is monophonic, unaccompanied sacred vocal music in Latin, intended for the Mass and Office. While only fragmentary musical sources survive, contemporary accounts and later comparative musicology suggest a highly ornate, melismatic style with certain Eastern (Byzantine) inflections and distinctive local liturgical usages. Gallican chant is historically important because its encounter and fusion with imported Roman chant in the late 8th–9th centuries helped give rise to the repertory we now call Gregorian chant.