Schoenberg’s son, Larry, 83, said the sheet music had been kept in a building behind his house. Both buildings were razed in the fires last week.

Other Schoenberg memorabilia was also destroyed, including photographs, letters and posters.

“For a company that focused exclusively on the works of Schoenberg, this loss represents not just a physical destruction of property but a profound cultural blow,” said Larry in a statement.

He described the collection as “essential” for musicians who rely on the “meticulously curated editions” of his father’s back catalogue.

Arnold Schoenberg was born into a Jewish family in Vienna in 1874. He went on to find huge success as a composer in Berlin before fleeing to the US in 1933 to avoid persecution from the Nazis.

He eventually settled in Los Angeles where he continued his groundbreaking compositions. He was known for atonality and his 12-tones technique which departed from conventional harmonies. He died in 1951 at the age of 76 in Los Angeles.

In a statement Belmont said it was hoping to create digital copies of the scores.

“We hope that in the near future we will be able to ‘rise from the ashes’ in a completely digital form,” the statement said.

Most of Schoenberg’s original manuscripts are held at a museum in Vienna, Austria.

Firefighters are still battling to control the huge wildfires in Los Angeles which began in early January. So far they have killed at least 24 people, destroyed thousands of buildings and forced tens of thousands of people to flee their homes.

Two major blazes are still raging in Los Angeles including the largest fire at the Palisades which has burned through more than 24,000 acres.