The Holy Week Office of Tenebrae

During the Sacred Triduum, the Matins and Lauds of the Divine Office are often sung in a haunting service known as the Tenebrae service (“tenebrae” meaning “shadows”), which is basically a funeral service for Our Lord.  On Wednesday evening/night, the Thursday office is traditionally said.  And in like manner, on the evening before, the Office for the next day is said.

During the Matins on Good Friday, one by one, the candles are extinguished in the Church, leaving the congregation in total darkness, and in a silence that is punctuated by the strepitus (a loud clatter intended to evoke the earthquake that was said to happen at the moment of death) meant to evoke the convulsion of nature at the death of Christ. It has also been described as the sound of the tomb door closing.

Consider purchasing a guide book to continue reading more on this aspect of the Triduum.  These booklets will allow you to learn in more detail the Liturgy of the Tenebrae Service for the Triduum:
http://www.cantius.org/go/webstore/product/tenebrae_service_booklets/