Good Friday Catholic Meditation. Diego Velázquez's crucifixion accompanied by Allegri's setting of Psalm 50, Miserere Mei - both masterpieces of the 1630s. Allegri's setting was originally deemed so sublime that it was only ever performed annually on Spy Wednesday and Good Friday in the Sistine Chapel - transcribing it or performing it elsewhere was punishable by excommunication. br br br Miserere mei, Deus: secundum magnam misericordiam tuam. Et secundum multitudinem miserationum tuarum, dēlē iniquitatem meam. Amplius lavā me ab iniquitate mea: et a peccato meo mundā me. br br Have mercy on me, O God, according to thy great mercy. And according to the multitude of thy tender mercies blot out my iniquity. Wash me yet more from my iniquity, and cleanse me from my sin.