Magnificat

The canticle of the Virgin, text ("My soul doth magnify the Lord") from Luke 1:46-55.  It consists of twelve verses, including the Doxology at the end.  In the Roman Catholic rites it is sung at the Office of Vespers by alternating choruses to one of eight recitation chants similar to the psalm tones, in connection with an antiphon that is usually somewhat more elaborate in style than the psalm antiphons.

The earliest composers of the Magnificat were Dunstable, Dufay, and Binchois.  Each of them composed the entire text, including the Doxology at the end.  After 1450 it became customary to compose only the even-numbered verses, the others being sung in plainsong.