Gregorian Chant Composer
Musicology (work in progress):The roots of many Christian liturgical chants lie deeply embedded in the worship of both Eastern (Orthodox) and Western (Roman Catholic) rites. Like the Kyrie eleison, the first part of the Ordinarium Missae, the fifth and first Ordinary chant, the Agnus Dei, originally served as part of a congregational litany of prayer within the Eastern church. The supplications of the Kyrie began the service, while those of the Agnus Dei helped conclude it. The Agnus Dei also had roots in the great Ambrosian liturgy of Milan, as a part of the Gloria in excelsis as sung in that church. The seventh century Pope Sergius I brought the Agnus Dei into a more prominent location within the Catholic Mass liturgy, as a chant sung while the celebrant physically breaks the Communion bread. By the eighth century in the Roman church, the Agnus Dei had ceased to serve as congregational music and was assigned to the schola, or choir. By the tenth century, the three iterations of the Agnus Dei had solidified into their final form.
That final form includes three prayers to Christ, whom John the Baptist had called "The Lamb of God, who taketh away the sin of the world." Twice the choir calls on the Lamb of God to have mercy upon us; on the third invocation, they ask dona nobis pacem (Grant us peace). In that form, with some exceptions, the celebrant and choir of every Catholic church for over a millennium have prayed during the Communion of every Mass celebration, night or day. Once a year, on Maundy Thursday, the third prayer for peace is omitted, and during Masses for the Dead (Requiems), it is replaced by a prayer for eternal rest to the departed.
Though the words remain constant, the Agnus Dei provided fertile ground for centuries of musical compositions. Since the tenth or eleventh century, composers have given to the Church some 300 different chant melodies for the Agnus Dei's simple prayer.
© Timothy Dickey, Rovi