Miserere, (full title: Miserere mei, Deus, Latin for "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 Holy Wednesday and Good Friday of Holy Week. [wikipedia]