Look for Part I. Regardez pour la 1e partie. Miserere by Italian composer Gregorio Allegri (also called "Miserere mei, Deus" - English "Have mercy on me, O God") 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 on Wednesday and Friday of Holy Week. 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 only allowed to be performed 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 (1650 - 1718, also spelled "Baj") in 1714. The Miserere is written for two choirs, one of five and one of four voices. One of the choirs sings a simple version of the original Miserere chant; the other, spatially separated, sings an ornamented "commentary" on this. Many have cited this work as an example of the stile antico or prima pratica. However, its constant use of the dominant seventh chord and its emphasis on polychoral techniques certainly put it out of the range of prima pratica. A more accurate comparison would be to the works of Giovanni Gabrieli. Mozart was summoned to Rome by the Pope, only instead of excommunicating the boy, the Pope showered praises on him for his feat of musical genius. Burney’s edition did not include the ornamentation or "abbellimenti" that made the work famous. The original ornamentations were Renaissance techniques that preceded the composition itself, and it was these techniques that were closely guarded by the Vatican. Few written sources (not even Burney's) showed the ornamentation, and it was this that created the legend of the work's mystery. However, the Roman priest Pietro Alfie...