A very familiar contraption used in the tinieblas is the tenebrario, what we call in Latin as the candelabrum triangulum and in English as the tenebrae hearse. It holds fifteen sockets and must support fifteen candles, which are one by one extinguished at the end of each psalm (nine from matins, five from lauds) until only the topmost candle remains burning. This topmost and centre candle is not seldom referred to as the Christ candle.
Below is the Lectionarium tenebrale pro Tridui Sacri matutinis proper to the schola singing the tinieblas, containing the notations of all the lessons sung during the office.
The tinieblas begins with all fifteen candles on the hearse and all six candles on the altar lit.
Matins is divided into three nocturns, with each nocturn having three psalms.
After each psalm, one of the candles on the hearse is extinguished. This gradual extinction of the candles, if we build on the premise of the Christ candle, signifies the departure and flight of our Lord’s apostles and disciples in the events close to His Blessed Passion. One by one light of the candles disappear, until only one—Christ alone in His sorrow, but firm in His promise of redemption—remains.
At the end of each nocturn, three lessons are sung. The lessons of the first nocturn come from the Prophet Jeremias; those of the second nocturn from Saint Augustine; and those of the third nocturn from Saint Paul.
After each lesson, a responsory is sung.
When the last responsory of matins has been sung, lauds customarily follow immediately, and the remaining five candles (with the exception of the centre candles) are extinguished at the end of each psalm.
During the Benedictus, the six altar candles are likewise extinguished, leaving the centre candle on the hearse as the only candle burning.
At the repetition of the antiphon to the Benedictus, this candle is taken and hidden away until the last collect has been said, and all the lights in the church are extinguished. The customary din and crash—in Latin, fragor et strepitus—follows, signifying the consternation of nature at the moment of our Saviour’s death, when the skies darkened and the ground shook. The noise only stops when the candle, hidden away before, is borne back to the hearse—a lone light in the darkness of the church, just as Christ is the lone Light Who shines bright amid the dense darkness of the world.
The rest of the office will be sung in the subsequent days.
Ut in omnibus laudetur Dominus.