Medieval religious anthem attributed to the Italian Franciscan Thomas of Celano, companion and biographer of St. Francis of Assisi, later used by the church in the liturgy of the deceased. The majesty and terrible beauty of this Gregorian music have inspired many composers. I remember the end of Berlioz's fantastic symphony. It is of an overwhelming beauty that also reminds us of the enormous subjugation of consciences to the religious power that threatened the final judgment: Day of Wrath, that day when time will be extinguished as David and the Sibyl attest.