One of only two surviving manuscript leaves from one of Mozart’s greatest compositions has been found in a private collection in England.

It is the cadenza for the first movement of the Sinfonia Concertante in E flat for Violin, Viola and Orchestra, K364, the 1779 masterpiece that catapulted him into the ranks of the world’s greatest musicians. It is the most important single leaf in the composer’s hand to have appeared on the market for decades.

Although a single sheet, it comes from Mozart’s greatest work for the violin and what is widely regarded as the greatest work by anyone for the viola. It is due to be auctioned at Sotheby’s in London next Tuesday, and is likely to exceed the auctioneer’s £100,000 estimate.

The reverse of the sheet will particularly interest scholars as it bears the playing parts for two horns, again in Mozart’s hand, for two unidentified pieces. Simon Maguire, senior specialist in Sotheby’s music department, said: “The Sinfonia Concertante is not only one of Mozart’s greatest works, it is also the key work that saw the young composer attain the level of musical accomplishment that has defined his reputation ever since.

“In spite of its importance, however, our familiarity with the piece today derives solely from published versions of the work, the entire original composing manuscript having been lost.”

The Sinfonia Concertante was composed when Mozart was 23. All that survives of the original score are the two leaves containing the two cadenzas and it is one of these that has now emerged. Although recorded in the literature on Mozart’s oeuvre, even Alan Tyson, the leading authority on Mozart, who pored over practically every surviving leaf of Mozart manuscript before his death in 2000, was never able to inspect this one.

Dr Maguire said: “What makes the survival of this sheet particularly noteworthy is the fact that cadenzas are perhaps the least likely part of any musical piece ever to be written down. Cadenzas were usually improvised, so there was no need for written guidance from composers. In this instance, because the concerto is a work for two instruments, Mozart worked it out in advance and wrote it out separately to avoid the two instruments improvising independently and clashing. Were it not for this, there would be no surviving manuscript for this work.”

The handwriting is swift and sketchy, reflecting that it was a first draft feverishly composed as Mozart went along. Dr Maguire said: “He’d not even time to fill in the note heads in many places.” Almost certainly, he added, Mozart wrote it for himself on the viola and his father, Leopold, on the violin.

About 175 lots in the Sotheby’s sale include the original draft of Schumann’s Piano Trio No 1 in D minor, 1847, a 25-page manuscript of a standard work in the chamber music repertory and the only autograph manuscript of any Haydn symphony to be auctioned in modern times.

Overture and finale

— Mozart’s father, Leopold, a composer and violinist, came from a family of architects and bookbinders

— Legend has it that Mozart wrote out the score of Allegri’s Miserere from memory after hearing it sung once in the Sistine Chapel in Rome

— He entered the service of the Archbishop of Salzburg, who mistreated and verbally abused him

— His head was too big, he had protruding eyes, a yellowish complexion and a face pitted with smallpox scars

— Only two of his six children survived

— Weeks before his 36th birthday, he had a streptococcal infection and renal failure, which led to cerebral haemorrhage and death

Source: Classic FM/Britannica

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