Angels Praising Almighty God

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.