Tenebrae (Latin for shadows) is a Christian religious service celebrated by the Western Church on the eves of Maundy Thursday, Good Friday, and Holy Saturday, which are the last three days of Holy Week. The liturgy of Tenebrae is characterized by the gradual extinguishing of candles while a series of readings and psalms are chanted or recited. Tenebrae is observed by the Roman Catholic Church (though not widely), and by some churches within the Anglican Communion. The name may also be used for various Holy Week services among Protestant churches.
The lessons of the first nocturn at Matins were taken from the Book of Lamentations. These lessons have been set to music by many composers, of whom the most famous are Palestrina, Tallis, Lassus, Marc-Antoine Charpentier, François Couperin, Ernst Krenek (Lamentatio Jeremiae prophetae, op. 93) and Stravinsky (Threni). In addition, the responses have been set by Lassus, Gesualdo, Victoria and Jan Dismas Zelenka. Musical settings are listed at length in the main article: Lamentations of Jeremiah the Prophet.
The lessons of the second nocturn were taken from the writings of St. Augustine, and the lessons of the third nocturn from the epistles of Paul the Apostle. These have been neglected by composers and are not provided with a special lesson tone in the Liber Usualis.
The office of Tenebrae was universal within the Roman Rite until the reforms of the Holy Week ceremonies by Pope Pius XII, which he introduced experimentally in the first half of the 1950s and made obligatory in 1955. He ended the practice of celebrating the Easter Vigil, and so the resurrection of Christ, on Saturday morning and moved the Holy Thursday Mass and Good Friday services to the evening or the afternoon. The solemn evening celebration of the next day's Matins and Lauds were thus ended.
Although it is thus no longer part of the official rites of the Catholic Church, except for Wednesday evening in cathedrals where the Chrism Mass is celebrated on Thursday morning, Tenebrae, or a shortened version in English, is still celebrated in some individual Catholic churches. and imitated by some other churches.
Protestant versions of Tenebrae service, particularly on Maundy Thursday or Good Friday, often contain readings from the gospels which describe the time between the Last Supper and the Passion of Christ. Another frequent element in Protestant Tenebrae services is the inclusion of the last seven sayings of Jesus, assembled from the various gospel accounts.
Some Protestant versions of the service combine Tenebrae with the communion service of Maundy Thursday and/or with the stripping of the altar. The stripping of the altar involves the removal of any decorative elements, such as any cloths on the altar, candles, or removable devotional objects. Immovable objects such as large icons, statues, and crucifixes, are covered by plain cloths or otherwise hidden in some manner. The stark appearance of the church mirrors the silence maintained at the end of Tenebrae. Often the elaboration of the acts of worship are reduced. The service may start with an organ and full choir, which is gradually reduced until the end of Tenebrae, at which point all depart in silence.