Mozart, Memory, and the Mystery of Allegri’s Miserere

Daniel Holland
Jul 20
5 min read

A classical composer in a red coat overlays sheet music titled "Miserere Mei Deus" by Gregorio Allegri. The background is light yellow. — Portrait of W. A. Mozart by Barbara Krafft

Once heard, it lingers. The soaring high C, often a rite of passage for boy trebles, has become one of the most recognisable and spine-tingling moments in all of choral music. Allegri’s Miserere is not only a beautiful piece, but also the subject of one of classical music’s most fascinating stories.

Today, it’s often performed during the season of Lent or Easter by cathedrals and choirs around the world. But for many years, this haunting setting of Psalm 51 was closely guarded by the Vatican, performed only within the walls of St. Peter’s Basilica, and never published for outside use.

So how did it escape into the public domain?

The answer, according to a well-circulated tale, involves a 14-year-old boy with exceptional ears, a photographic memory, and a name that would soon become synonymous with genius: Wolfgang Amadeus Mozart.

Allegri’s sublime Miserere has been a choral favourite for centuries.

Easter in Rome, 1770

In the spring of 1770, the Mozart family was travelling through Italy. Young Wolfgang, just fourteen, was on a grand tour with his father Leopold, a composer and violinist in his own right, who was determined to show off his son’s precocious talents to Europe’s musical elite.

When they reached Rome during Holy Week, the city was alive with religious ritual, art, and music. Among the most treasured experiences on offer to the faithful, and music lovers alike, was the Tenebrae service at the Vatican. Here, in the Sistine Chapel, a small choir would sing Miserere mei, Deus by Gregorio Allegri, a piece composed in the 1630s for the exclusive use of the Papal Choir.

The piece was strictly reserved for use in the Vatican. In fact, transcribing or performing it elsewhere without permission was reportedly forbidden, under pain of excommunication.

Young Mozart, attending the service with his father, listened carefully to the entire performance. Then, returning to their lodgings, he did something extraordinary.

Easter in Rome, 1770

In the spring of 1770, the Mozart family was travelling through Italy. Young Wolfgang, just fourteen, was on a grand tour with his father Leopold — a composer and violinist in his own right — who was determined to show off his son’s precocious talents to Europe’s musical elite.

The piece was strictly reserved for use in the Vatican. In fact, transcribing or performing it elsewhere without permission was reportedly forbidden, under pain of excommunication.

Young Mozart, attending the service with his father, listened carefully to the entire performance. Then, returning to their lodgings, he did something extraordinary.

Young person in a red coat playing a keyboard with sheet music visible. They have a composed expression. Background is dark. — Young Mozart

Writing from Memory

As the story goes, Mozart sat down and wrote out the entire piece from memory. Five voice parts, multiple musical sections, and intricate harmonies — all recalled after a single hearing.

It’s a remarkable claim, and understandably, some have questioned its plausibility. But it’s also worth remembering that Mozart wasn’t your average teenager. By the age of five, he had already composed short keyboard pieces. By six, he was performing before European royalty. His ear for music was almost without equal.

According to several 19th-century sources, Mozart may have attended a second performance of Miserere at St Peter’s later that week, possibly to check his transcription. That kind of double-checking, even for someone with his memory, makes the story far more believable.

What he produced was almost identical to Allegri’s score, including the famous ornamented high C passages, which had never been published.

A Piece Once Shrouded in Secrecy

Part of what made Miserere so mysterious was how tightly it was kept within the Vatican. It had become something of a sacred secret — passed down through generations of papal singers and never distributed to the outside world. The only exceptions to this were a few handwritten copies gifted to important figures, such as the King of Portugal and the Emperor of Austria.

The Sistine Chapel's ornate ceiling features vivid biblical frescoes. Intricate patterns adorn the floor and walls in a grand, historic setting. — East side of the Chapel, from the altar end

Yet none of those versions were widely circulated, and the general public had no access to the music until Mozart’s score brought it into the open.

His father Leopold reportedly mentioned the incident in letters and journals, though not always with much elaboration. Over time, the tale became legendary, not only for what it said about Mozart’s abilities, but for how a beautiful piece of music finally became available to the wider world.

What Makes Miserere So Special?

Composed by Gregorio Allegri in the 1630s, Miserere mei, Deus is a setting of Psalm 51, traditionally sung on Maundy Thursday and Good Friday during Tenebrae, a solemn service where candles are gradually extinguished.

Musically, it’s structured for two choirs: one of five voices (soprano, alto, two tenors, bass) and a second trio. The famous soaring high C, sung by a treble or soprano in one of the sections, is actually a later embellishment added during the Baroque period — possibly even after Allegri’s original composition.

The haunting, meditative quality of the piece, paired with the acoustics of the Sistine Chapel, created an atmosphere that many described as transcendent. It wasn’t just a piece of music — it was a sacred experience.

Fact or Legend?

Is the story true? There’s no definitive documentation from the Vatican confirming that Mozart “stole” the piece or broke any official rules. It’s also not clear how strictly the prohibition against copying was enforced by 1770.

What we do know is that Mozart’s transcription helped popularise the piece outside Rome, and it was soon performed elsewhere in Europe. Later versions of Miserere were published with adjustments and improvements, and the piece quickly became a favourite of choirs and listeners everywhere.

The Vatican, for its part, didn’t seem particularly upset. In fact, not long after the episode, Pope Clement XIV awarded Mozart the Order of the Golden Spur, a papal knighthood, which suggests there were no hard feelings.

A Legacy Shared with the World

Thanks to Mozart’s remarkable memory and musical instincts, a piece once confined to the candlelit walls of St Peter’s now fills cathedrals and concert halls around the world. Miserere remains one of the most performed and recorded choral works of the sacred repertoire — especially during Lent and Holy Week.

And although there may be a little myth mixed in with the facts, the heart of the story remains inspiring. Whether it happened exactly as described or not, it reminds us of the incredible power of human memory, musical talent, and youthful curiosity.