PARIS (Reuters) – A fragment of music by the Austrian composer Wolfgang Amadeus Mozart had its first known public performance on Thursday in the western French city of Nantes, where it had lain for years in a municipal library.

The two pieces with a combined duration of under two minutes were played on the violin by Daniel Cuiller, artistic director of the baroque music ensemble Stradivaria before a small audience of journalists and friends.

The one-page score, which was a fragment from a mass, was donated to the Nantes library by a private collector at the end of the 19th century but had previously been thought to be a copy rather than an original.

It was authenticated in 2007 by Ulrich Leisinger, a specialist from the Mozarteum University in Salzburg, who estimated that it could have a value of up to 200,000 euros ($259,500) at auction.

“The sheet has all the characteristics of Mozart's handwriting,” Leisinger said.

He said the sheet had also been certified by an expert in 1839, “at a time when Mozart was certainly considered as a highly respectable composer but certainly not as an icon.”

“At the time, no one would have had an interest in making a forgery,” he said.

Mozart was one of the most prolific classical composers. He died in 1791 at the age of 35, leaving over 600 known works.

(Reporting by Guillaume Frouin; writing by James Mackenzie; Editing by Richard Balmforth)