The Magnificat is a ‘canticle’, a non-metrical, song-like passage of text drawn frombooks of the Bible other than the Book of Psalms. The Magnificat – the Song of the Blessed Virgin Mary – comes from the Gospel of St Luke, 1:46–53, and represents Mary's joyful response to the message given her by the Angel Gabriel that she was to bear the son of God. In the Catholic liturgy this canticle was set to be read or sung daily towards the end of the main evening Offce of Vespers. It forms the climax of the service, and while it is being sung a priest censes the altar. The Magnificat is preceded by the singing of an antiphon specific to the particular day on which it was being performed, and followed by the ‘Gloria Patri’ and a repetition of the antiphon. This whole unit is then followed by a prayer and the dismissal of those who have celebrated Vespers.

The text of the Magnificat is laid out in the Liber Usualis (an abbreviated compendium of texts and music for the Mass and Offce) as follows. (The English version is the one given in the Book of Common Prayer.)