In the Middle Ages, the Church kept Advent as a season of great solemnity – a time in which to meditate upon the ultimate issues of death, judgment, hell and heaven. Advent, though, was also a time of great rejoicing. For Christ would come, not only as Judge, but also as Savior, and would usher in the Kingdom of God. Advent, therefore, provided a vivid preparation for Christmas. Processions from West to East, and the use of lights, spoke of the Church’s hope in the coming of Christ – the Light of the world – to banish sin and darkness. This Service is structured around the great Advent Antiphons, known as the Great ‘Os’. These were sung originally as Antiphons to the Magnificat at the Evening Office from 17th to 23rd December, and have provided a rich source of devotional imagery in Advent. The second word of each antiphon yields an acrostic: read in inverse order from the last to the first stanza, the words begin with the letters ERO CRAS, which is Latin for “I shall be present tomorrow.” If one antiphon is sung each day, the full text of the acrostic is revealed only on the day before Christmas Eve. The readings and music serve to complement the Antiphons, and help us reflect on the theme of the Christ who comes to judge and save his people. Even so come, Lord Jesus