The phenomenal success of Dan Brown’s The Da Vinci Code has unintended consequences that are wholly beneficent. Roslin Chapel, seven miles from Edinburgh, now welcomes shedloads of hot-eyed tourists on the trail of the Holy Grail. This is excellent news for the restoration fund, which has £2m more to be raised.

Wordsworth and his sister Dorothy sheltered from a storm in Roslin Chapel in 1803. He retired to the nearby pub and knocked off a sonnet, while she described in her diary the intricate stone carvings of leaves, flowers and faces all over the chapel’s interior, and the uncanny effect of live green ferns sprouting around identical algae-tinged stone ones. The chapel was “exquisitely beautiful” but “as nothing is done to keep it together, it must, in the end, fall”.

It had been falling ever since the Reformation. Cromwell’s troops, sacking nearby Rosslyn Castle, used it as stables. When Queen Victoria visited, she opined that it should be saved for the nation, and periodic efforts – some ill advised – were made to restore this jewel of 15th-century architecture. Some of its meaning is still to be interpreted. Patterns engraved on protruding stone cubes may be musical notations, as on the recently decoded medallions in Stirling Castle.

Roslin Chapel’s renaissance has been sealed by Shadwell Opera’s sell-out production, within the shadowy walls, of The Magic Flute, part of the Edinburgh Fringe. This was eerily apt, since Roslin has strong historical links with Freemasonry and the Knights Templar, and Dan Brown is not the first to name it as the Grail’s resting place. Shadwell Opera is a Cambridge undergraduate outfit, and the costumes were school-pantomime – dressing gowns, jeans, boiler-suits. Members of the Brotherhood wore silver DVDs on strings round their necks to represent pseudo-Masonic emblems. Sarastro, as head honcho, sported a large vinyl LP. This was entirely satisfactory, as was the libretto in a frisky version by the versatile Kit Hesketh Harvey (of Kit and the Widow).

So far, so playful. But the confident direction by Jack Furness, the crisp, full-blooded singing, and the elan of the minimal orchestra would have done credit to any professional company. Aidan Coburn, Shadwell’s shock-headed musical director and conductor, is like a come-again Simon Rattle.

. . .

James Naughtie, announcing the Man Booker shortlist on Tuesday in London, spoke euphorically about the “pure, energising stream of talent” he and his team of judges found in their chosen six. October 6, when the winner is announced, is also the date for the announcement in Toronto of the shortlist for the Scotiabank Giller Prize, Canada’s equivalent of the Man Booker.

Reading almost 100 works of Canadian fiction, as one of the judges for this year’s Giller, is a life-enhancing experience, and gives a glimpse into the culture. The Canadian for “gutter” is “eavestrough”, which is picturesque . Everyone is wearing a “tuque”, or “toque”, which in English-English suggests the lofty headgear worn by Queen Mary but is actually a little woolly hat. And in the holiday cottages among Ontario’s northern lakes and forests – evidently, the prime setting for emotional turmoil – they sit, brooding, on Muskoka chairs. (Look those up on the net.)

. . .

There is a convention in Canada of appending to your novel a list of people who are fulsomely thanked for their support, starting with the book’s editor – unfailingly sensitive, creative and patient – plus family, friends and first readers. These last are generally fellow members of a writing group, who have contributed insightful modifications.

But has any major work of art ever been produced by committee? Readers may wonder whether a writer’s vision and voice may not get ironed out by such proactive input, and indeed there is a striking homogeneity in the muddy middle range of novels, often about families down the generations with multiple points of view and flashbacks to Granny’s youth in the Ukraine or wherever.

The US, too, is a nation of immigrants, but American novelists do not bang on so about their heritage and antecedents. Brits do, but differently, less personally. As it happens, all the Man Booker shortlisted novels are set back in time.

Apart from brilliant Giller contestants, there are – as Naughtie boldly said about the Man Booker entries – “unbelievably dreadful” ones. It seems in Canada that you only have to write a novel to get grants from the Canada Council for the Arts and from your provincial Arts Council, who are also thanked. Complaints were once voiced that most shortlisted Giller novels emanated from just three big-name publishers, all owned by Bertelsmann, and that virtually every winner lived in the Toronto area. Now, many of the submitted authors, and their rugged subject matter, hail from Saskatchewan, Manitoba, Nova Scotia, Newfoundland. That’s maybe because small publishers too are now subsidised, and they proliferate. If you want to get your novel published, be Canadian.

Peter Aspden is away