The Penitential Psalm 51(Greek numbering: Psalm 50), traditionally referred to as the Miserere, its Latin incipitis is associated with Ash Wednesday as a scripture reading in both the Revised Common Lectionary and the Roman Catholic Lectionary. The psalm is frequently used in various liturgical traditions because of its spirit of humility and repentance. The psalm’s opening words in Latin, Miserere mei, Deus, have led to its being called the Miserere Mei or even just Miserere. One of the best-known settings of the Miserere is the17th century version by the Roman School composer Gregorio Allegri. According to a famous story, Wolfgang Amadeus Mozart, aged only fourteen, heard the piece performed once, on April 11, 1770, and after going back to his lodging for the night was able to write out the entire score from memory. He went back a day or two later with his draft to correct some errors. The form of this Penitential verse Anthem follows the musical structure of the three sectioned ternary ABA form, which also represents the Theological concept of the union of three persons, the Father, Son, and Holy Ghost, in one Godhead. The opening Adagio is recapitulated in verse 16 � For thou desirest no sacrifice, else I would give it thee;�and the work closes with a short coda. The middle section which encapsulates the very core of the Psalm is worked in various key changes and tempi.