The ghosts of infamous 17th century East Riddlesden Hall family the Murgatroyds are likely to be stirring in their graves next week.

For the historic Keighley mansion will be turned into a theatre by Haworth West Lane Baptist operatic group with their performance of Gilbert and Sullivan's Ruddigore.

The musical about a cursed Yorkshire family is said to be based on the lawless lives of the mad Murgatroyds, who lived in the hall and were excommunicated for their evil antics. And 350 years later the uncanny link is living on - in the guise of Bill Bairstow and his clan.

Bill, head teacher at Eastwood School, Keighley, has worked out that his family is linked to those crazy cousins - tenuously maybe, but true.

And when the curtain goes up next month, it will be like returning home for Bill, his wife Linda, daughters Emma, 17, Lucy, 15 Amy, 14, and his 84 year-old dad, Ron.

The National Trust, which now owns East Riddlesden Hall and the Airedale Barn in its grounds, has invited the Haworth group to perform, especially because of the operatta's link with the Murgatroyds. Their shows are usually in Haworth.

Appropriately, Bill will be playing Sir Despard, a character broadly modelled on the characteristics of the Murgatroyds. Linda will be performing as his jilted wife, Mad Margaret Lucy will be acting as Zora, while her sisters take on the role of bridesmaids. Grandad Ron plays the vicar, a role which, like the rest of the parts, involves dancing.

"It's a wonderful experience having the whole family involved," said Bill, of Hope Hill, Baildon. "This is the first time my dad has joined in anything like this although he has sung in choirs for many years. It's a rare opportunity for us all,"

"I've been a member at Haworth for 20 years but met Linda when we were playing the same roles for Bingley Gilbert and Sullivan Society at about the same time. It was the first time we acted together."

Bill has been digging into his family past and believes the link with the Murgatroyds comes through the Halifax branch. "During my search I discovered that, about 1550, one of the Murgatroyd brothers married a Bairstow and there have been connections between the two families since that time," he said.

WS Gilbert is said to have picked up the story of the Murgatroyds during one of his stays at the hall. His tale of Ruddigore, first performed in 1887, depicts Sir Despard as the victim of a witch's curse. He is forced to commit a crime a day or suffer a terrible death at the hands of his ancestors.

"Fortunately for me, the operetta has a happy ending," Bill said.

Samantha Lawson, East Riddles-den Hall's visitor services manager, said: "We invited Haworth to perform here because of the link between the musical and the story of the family. And there are a lot of people in the area who have family links with the Murgatroyds."

The show, directed by Michael Lofthouse, will be performed from next Tuesday to Saturday, November 17, starting at 7.30pm with a 2.15pm matinee on Saturday. Tickets are available by telephoning (01535) 643425.