Country: Country Matters - All set for a role in the hay

O pera in a barn? Cosi Fan Tutte in a cowshed? Why not? If you love music, have money and also enjoy baiting the local planning authority, why not convert your outhouse into an opera house?

That is precisely what Martin Graham has done at Longborough, near Stow- on-the-Wold, and his third season will open later this month, with Mozart, Strauss and Wagner on the bill. If anyone accuses him of aping Glyndebourne, he couldn't be more delighted. "I'm sure it was the novelty of having an opera house in his garden that fascinated John Christie," he says.

Mr Graham came to Longborough as a child 50 years ago, and has lived in or near the village ever since. An ex-farmer who describes himself as a "cowboy builder and a dealer in property", it appears that he has shifted his ground more than a few times. His present home looks, at first sight, more or less like a traditional Cotswold farmhouse, but he built it himself, starting in 1988.

Did I also hear him call himself a spiv? By implication, yes. "You know who founded the Welsh National Opera? A second-hand car dealer. It takes the spivs to do it!"

A cheerful and ebullient fellow, he specialises in teasing, and making cryptic remarks - as when he suddenly announces: "I'm walking to Glyndebourne."

"Goodness," I said. "Sussex must be a fair way from here. About a hundred miles?"

"A thousand, the way I'm going."

"How's that?"

"Well... [as if it were perfectly obvious] I'm going via north Wales and over the Pennines to Norfolk - long-distance footpaths all the way. I've kicked off already. Starting from Chepstow, I've got almost to Prestatyn on the Offa's Dyke path."

Walk as he may, he is no conventional countryman. Does he shoot? "Oh no! I hate that." Hunt? "Certainly not! A lot of the people who go hunting aren't quite... You see, we've got half the City living down here." He is particularly scornful about the Countryside March of 1998, when 300,000 "rustics" paraded through London. "What was that about? Nobody knew what they were marching for. All the toffs were there, and they got all these work dopes on their side."

His interest in music was kindled by a curious character who turned up in the village when he was a boy. Jack Wilsher, an East End cockney who was entirely self-educated, had taught himself not only to speak French and German, but also to play violin and piano, and sing Lieder. He would walk up the village street singing a Schubert song at the top of his voice, and then challenge his young companion: "Nar then, Mar'in, what was that?"

Mr Graham's aim now is to share with others the delight that music has given him. For many years he and his wife Liz have been putting on chamber concerts at home, but it was only recently that he conceived the idea of an opera house, after hearing an amateur performance of La Boheme at Stratford.

In the Seventies, he had built a barn here - "a hideous thing!" - to house cattle; but the animals have long since gone, and he realised that the structure was big enough to accommodate a good-sized stage and audience. He then wondered if the planners would allow it. It so happens that one of his favourite hobbies has been "lying in bed reading long leases" - papers he describes as "the most exciting documents since Jane Austen, because there's money to be made from them". He concedes that it's an odd pursuit, but he has done well by combing through the small print and spotting property development opportunities others have missed.

Looking at the papers relating to his barn, he realised that he had built it under a planning instrument called the General Development Order of 1976. There was nothing in that regulation to prevent him changing the building's use, so in 1996 he went ahead and converted it, getting John Whitton, an architect, to transform the entrance end with an impressive, neo-Palladian facade.

The barn's classical pediment and white pilasters against a deep- pink background create a striking effect - even if the asbestos roof and wooden upper wall of the barn, which you see first as you approach, remain unmistakably agricultural. His wife's bantams, rushing to greet any newcomer, enhance the rustic component of the picture.

Inevitably, the planners did object - and so did Mr Graham, when the Cotswold District Council's enforcement officer came on to his property, unannounced and uninvited, and took notes, while he himself was on holiday. A furious row erupted; the council officer recommended that the building be demolished, but Mr Graham knew his ground and, in the end, saw the planning committee off.

"It was easy meat," he says. "Nobody loves planners - it's a horrid business to be in. But it all ended all right." Not being one to lose an opportunity, he still embellishes his own postcards, which carry a picture of the Longborough opera house, with the legend, "Demolition sought by Cotswold District Council 1998".

Since the opening season, facilities have been steadily improved, not least by the installation of 500 plush, crimson seats given away by Covent Garden when refurbishment of the Royal Opera House began last year. The acoustics are said to be excellent, because, by good luck, the volume of the auditorium works out exactly at the optimum figure of seven cubic metres per person. As yet he has no catering facilities, but visitors can eat their picnic suppers on an attractive, sloping grass field.

When I visited recently, the site was in chaos, with building materials everywhere. Twelve men were at work, but when I expressed doubt about everything being ready for the start of the season on 25 June, Mr Graham brushed my worries aside, remarking that, last year, the capacious orchestra pit had been dug out and built in only a week.

"I took the family to Ireland for a few days," he recalls. "I said to my man, it needs to be 15 metres long, five wide and two deep. When I came back, there it was, done."

The proprietor being who he is, I feel sure everything will be all right on the night. "Confidence!" he cried. "That's what it's all about. That's what gets you through."