During the Holy Triduum, the night office of matins and the morning office of lauds have a special liturgy, called Tenebrae. The Office of Tenebrae takes place on the mornings of Holy Thursday, Good Friday, and Holy Saturday, or they are anticipated and take place in the evening of Spy Wednesday, Holy Thursday, and Good Friday.The Office is made up of psalms, lessons and readings, and sung responses.A triangular structure, called a hearse, has fifteen candles. One candle is extinguished at the end of each psalm.Here, the sisters sing one of the responses in Gregorian Chant.A canon sings one of the lessons.At the end of the fourteenth psalm, there is one lit candle remaining as well as the altar candles.The altar candles are then extinguished one by one during the chant of the Benedictus at the end of lauds.The last remaining candle is carried behind the altar. There is a time of silence. When the candle is brought forth from behind the altar, there is a great noise produced in the sanctuary, representing the chaos in nature after Our Lord's death. The candle is then extinguished, leaving all in darkness and silence.
