This is a beautiful performance by the
Tenebrae Choir of Gregorio Allegri's setting of
Miserere mei, Deus (Have mercy upon me, oh Lord). Conducted by Nigel Short and filmed at St. Bartholomew the Great in London, the video was published in 2018.
Here the choir members are distributed in the nave of the cathedral: one soloist is up in the mezzanine and four are at a remove in the nave proper, back from the chancel where the main choir sings. So far the film of this particular performance has been viewed over 2 million times.
Allegri's setting of the Miserere is thought to have been composed in the 1630s. The text is King David's celebrated prayer of repentance for his sins of adultery and murder. It is one of the seven so-called Penitential Psalms from the Book of Psalms in the Bible. It is number 51 in the KJV Bible, 50 in the early Greek and Latin versions.
The psalm has been incorporated in whole or in part into various rites of Judaism, Roman Catholicism, Eastern Orthodox and some Protestant denominations. Notable composers across the centuries who have set this psalm or adaptations of it to music include Orlando di Lasso, Josquin des Prez, J.S.Bach, Giovanni Croce, William Byrd.
Some history on the name of the choir performing in this video: the Latin word
tenebrae means "darkness" in English. In Christianity it is also the name of a religious service that may be held during one of the three days preceding Easter. The service itself varies depending on denomination. It includes sung or recited liturgy or seasonal readings during which time there is a gradual extinction of lit candles, and in the final darkness, the making of a loud noise (slamming a Bible shut or tolling bells) to represent the earthquake said to have occurred at the death of Christ.