Up for auction, the manuscript has been described as the most important to be sold in the last decade.

A manuscript that Mozart wrote in 1772 has been discovered in South America. The article has rich provenance, having been owned by a variety of collectors and smuggled out of Germany by a Jewish refugee on the eve of WWII.

The composer was 16 when he started to write the Kyrie in C Major, but abandoned it after just five pages. Knowing that the authorities would confiscate valuables and currency, Rudolf Götz bought the manuscript cheaply and subsequently fled Nazi Germany.

“The family couldn’t take obvious valuables or currency with them when they left so they took this,” said Simon Maguire, Sotheby’s musical manuscript specialist. “We don’t know how much it cost but in the 1930s something like that didn’t make a lot of money.”

No matter the cost, the Jewish musician boarded a ship bound for South America, with just one reminder of his homeland. To protect its provenance, Götz separated the manuscript from its title page – a wise foresight given the ship and its cargo were torpedoed before reaching South America.

Despite the tumultuous circumstances with which it was originally...