Gregorio Allegri’s ‘Miserere mei, Deus’ is one of the most devastatingly beautiful pieces of choral works ever composed. It is perhaps the best known example of late-Renaissance music, but, if the strictures of the Papacy had been followed, it would have been unknown outside of the confines of the Sistine Chapel.
The piece was written sometime before 1638 and had become so famous in the next century that the Papacy banned, on the pain of excommunication, its performance outside of the Sistine Chapel. For many years, the only way of hearing the music would be to attend one of the two Holy Week matins services in which it was performed.
Rarely can the senses have been so ravished – the Baroque splendour of Michelangelo’s Sistine Chapel, the soaring voices of the Papal Choir and the otherworldly genius of Allegri’s composition provide the evocative setting. At 3 am, the service would begin, with the light of 27 candles burning brightly, dancing sacred light off the newly painted frescoes. They were extinguished one by one until only a single flame was left. The service was often led by the Pope, and must have been an experience of religious ecstasy for the Holy Week pilgrims. Rarely can the divine have been so sumptuously invoked.
It was this expression of devotion that was so jealously guarded by the Supreme Pontiff. Whether out of fear of the music’s impact being diluted or a simple desire to retain the celebrated work within the confines of Rome and thereby ensure the attendance of devotees, the Papacy forbade the work to be written down or sung outside of the Sistine Chapel.
The music remained largely confined to Rome until its next brush with genius. On 11 April 1770 Leopold Mozart and his son Wolfgang arrived in Rome as part of their grand tour of Italy. They had arrived in Holy Week, in time for Easter and in time to attend the Wednesday Tenebrae in the Sistine Chapel and hear the famous Miserere.
The 12-year old prodigy then returned to his lodgings and committed the piece to paper entirely from memory. He returned to the Sistine Chapel on Good Friday to review his manuscript, and made a few minor corrections. His father boasted of his son’s achievements in a letter to his wife dated 14 April 1770:
"…You have often heard of the famous Miserere in Rome, which is so greatly prized that the performers are forbidden on pain of excommunication to take away a single part of it, copy it or to give it to anyone. But we have it already. Wolfgang has written it down and we would have sent it to Salzburg in this letter, if it were not necessary for us to be there to perform it. But the manner of performance contributes more to its effect than the composition itself. Moreover, as it is one of the secrets of Rome, we do not wish to let it fall into other hands…."
Mozart may not have let loose the secrets of Rome, but the composition did soon after find its way to London via Dr Charles Burney. And, once revealed, the music became widely available. It is unlikely that Mozart was the sole conduit for its circulation - written copies had been made available to the Holy Roman Emperor, for example - but Mozart was the composer best able to do justice to Allegri's composition.