Miserere, full name "Miserere mei, Deus" (Latin: "Have mercy on me, O God") by Italian composer Gregorio Allegri, is a setting of Psalm 51 (50) composed during the reign of Pope Urban VIII, probably during the 1630s, for use in the Sistine Chapel during matins, as part of the exclusive Tenebrae service on Wednesday and Friday of Holy Week. The service would start usually around 3AM, and during the ritual, candles would be extinguished, one by one, until one remained alight and hidden. Allegri composed his setting of the Miserere for the final act within the first lesson of the Tenebrae service.
It was the last of twelve falsobordone Miserere settings composed and chanted at the service since 1514 and the most popular: at some point, it became forbidden to transcribe the music and it was allowed to be performed only at those particular services, adding to the mystery surrounding it. Writing it down or performing it elsewhere was punishable by excommunication. The setting that escaped from the Vatican is actually a conflation of verses set by Gregorio Allegri around 1638 and Tommaso Bai (also spelled "Baj"; 1650–1718) in 1714.
Other articles related to "miserere":
... Book of Common Prayer, and is used in Ivor Atkins' English edition of the Miserere(published by Novello) ...