This form of the monastic office (matins and lauds) is commonly adapted for congregational use during Holy Week. The office is structured around psalms, readings, and responsories. A distinguishing characteristic of this service is the series of readings from Lamentations which appear early in the office. The distinctive ceremonial of Tenebrae includes use of fifteen lighted candles, often set on a special, triangular stand. One candle is extinguished as each of the fourteen appointed psalms is completed.
One candle is extinguished as each of the fourteen appointed psalms is completed. The fifteenth candle, symbolic of Christ, is left lighted at the end of the final psalm. But it is carried away to be hidden, which signifies the apparent victory of the forces of evil. A sudden loud noise is made at the end of the service, symbolizing the earthquake at Christ's death. The lighted candle is then restored to its place, suggesting Christ's eventual triumph. The BOS includes Tenebrae as an option for use on Wednesday in Holy Week.