The text originally comes from Psalm 80:2. It is traditionally used on the third Sunday of Advent, the 'Gaudete' or 'Rejoicing' Sunday, when penitential exercises are suspended to symbolize the coming of the joyous Christmas season. The text, Excita, Domine, is also used in some churches for the 'Stir Up Sunday' on which Christmas puddings are made and literally 'stirred up'. The beginning of the piece quotes the 'Alleluia' from the original chant, and then moves from the ...