A call has gone out for people to check shelves and lofts for a missing opera.
The original score of Gilbert and Sullivan's Utopia Limited was sold in 1915, but its whereabouts are unknown.
Gilbert and Sullivan created 13 operettas that are still performed today, but the manuscript for Utopia Limited has been lost.
Musical researcher Colin Jagger has been tracking down their original scores, saying current copies often have mistakes and omissions.
"The (current) score (of Utopia Limited) is completely unreliable. The only way (to be sure) is to go to Sullivan's autograph manuscript," he said.
"It seemed to me that the time is long overdue to give these materials proper editions which are free."
Omissions, changes and mistakes
When the operas were first created, copyright law, as understood today, barely existed, and so the company that performed the works, D'Oyley Carte, kept tight control of the scores and any copies.
The versions used today often reflect how D'Oyley Carte performed the works, rather than Gilbert and Sullivan's original intentions.
Some songs have disappeared altogether and, Jagger says, the scores have a multitude of omissions, changes and mistakes.
The objective now is to return to the originals, and create complete and corrected scores.
But the project cannot be finished until the lost opera is found.
"All of these manuscripts…you can access mostly in the UK or one or two in the US. So I can go into the British Library and I can look at the Grand Duke in Sullivan's own hand, and I can take photographs of it.
"I can study it away from the library as well. And I can go (online) to the Morgan Library in New York… and I can see a beautifully done copy of the manuscript of Safe Trial by Jury. They're all there except for one."
Utopia Limited is one of Gilbert and Sullivan's less successful works.
It's a story based around the problems and consequences of the introduction of limited liability laws in the 19th Century. Essentially, it's a satire about business people leaving their creditors in the lurch.
The score was sold at auction in 1915 for 50 guineas to Sir Robert Hudson of Hill Hall in Essex.
Sir Robert died in 1927 and Hill Hall went on to house prisoners-of-war, and later became a women's prison.
Where the score for Utopia Limited went is a mystery.
'It's probably out there'
Colin Jagger is convinced it has survived and is sitting on a shelf somewhere, telling the BBC: "We have no idea where it is now."
"It could be in a loft or it could be on a shelf. The title is Utopia Limited. It's very thick, a bit bigger than A4, not quite as big as A3, and it's hardbound in leather and handwritten.
'It would be awful to think it had been thrown away.
"So I think it's probably out there but somebody maybe doesn't know they've got it or they might not know who Gilbert Sullivan are."
Mr Jagger has asked that anyone with any information about the missing score contacts him at [email protected].
