On the eve of my departure for the Edinburgh International Film Festival, I attended a BFI Southbank event organised as part of the London Festival of Architecture. The feeling that there's a festival around every corner can lead to blasé complacency but this event was special – a rare evening devoted to the great contrarian and critic Iain Nairn, an unmissable opportunity to see two of the many wonderful films he made for the BBC in the sixties and seventies. The packing could wait and, anyway, I needed cheering up as my preparations for Edinburgh had earlier taken an unexpected, untimely turn when a light-fingered, fleet-footed urchin divested me of some extremely expensive and useful technology. Fortunately, the scaly thief only temporarily robbed me of the power of speech for I'd love to talk to him one day (such things I'd tell him, such questions I'd ask). It may be best we never meet as I suspect he'd finally relieve me of that most perfect form of mobile communication and that our exchanges would disintegrate into physical conversation.

Iain Nairn possessed the gift of fiery speech but lost it in the bottom of a glass. He became the tragic embodiment of Orwell's dictum that a man may take to drink because he feels himself a failure and then fail all the more completely for that. While in full command of his extraordinary faculties, he deployed them to telling effect in his acutely perceptive, often mordantly funny attacks on mediocrity in structural design, town planning and, by inference, culture and politics. In the first of the two films we watched in NFT3, Oxford-Padua (1970) from the 'Nairn's Europe' series, he compares the university cities and concludes that use and art combine in sweeter concord in Padua, where the student population moves among the broad citizenry with less colonising swagger and aloof arrogance. In the second, Football Towns: Huddersfield and Halifax (1975) from the 'Nairn's Journeys' series, he tots up the strengths and weaknesses of the Northern towns and declares Halifax the 5-2 winner,  because it has "expressed itself" better than its more timid neighbour.

While attending the Edinburgh International Film Festival, I'm staying in a friend's tenement flat in Glasgow. As I touch-type on an 'ancient' borrowed laptop, I can see, almost touch, the cupolas and spires of Glasgow University (my alma mater) high on its hill and, lower and closer, those of the Kremlinesque Kelvingrove Art Gallery & Museum. It is one of the great vistas of Europe. One-nil to Glasgow. I wish I still had my iPhone to capture the splendour of the view but my seven-year old Nokia doesn't cut the mustard and nor, from where I'm sitting, does Edinburgh. Ok, ok, it has an elegant carapace, that cliff face of buildings above Waverley Park, and the grandeur of its own hilltop castle. One-all then.

I write less easily when I'm far from home and doing it on the hoof (like Douglas Adams, "I love deadlines. I love the sound they make as they whoosh by"). I miss the time to cogitate, the solid anchor of my desk, above all, the guidance and support of familiar books and films. Here, at least, I can reach out to William McIlvanney and Oscar Marzaroli's Shades of Grey: Glasgow 1956-1987, a sublime survey in words and images fully the equal of James Agee and Walker Evans' mighty co-operative effort Let Us Now Praise Famous Men. McIlvanney begins: "People trying to be honest will have a clear sense of cities in inverse ratio to the time they've spent there. The longer you are acquainted with a place the more you know you don't know it . . . Glasgow? What I don't know about Glasgow would fill several books. Some people might say it has. What I think and feel about Glasgow, after more than thirty years' close acquaintance, is very involved: the onion, memory. I peel it."

What chance have I of saying anything useful about Glasgow, after just twenty-five years of passing acquaintance, if one of her most eloquent sons baulks at the impossible task of expressing his feelings and thoughts about it? None, but I can salute William McIlvanney's attempt. Cities, of course, are perpetually changing, so to write about one is to aim at a moving target; McIlvanney, like Iain Nairn, took aim at something immutable: the character of cities and of the people who shape it. Critic and filmmaker Jonathan Meades has argued that Nairns' acute sense of place, his gift for expressing it and ability to realize the emotional power it contains "made him a great poet of the metropolis." Meades, who is no slouch himself, was scheduled to join us for the BFI's Nairn event. A health scare deprived us of his company but he joined us by Skype from Marseilles. During the evening, he finessed the observation above by layering in another rare talent Nairn and McIlvanney shared: the knack of drawing out the relationship between places and people. When Meades was asked why so few architects write well about architecture, he replied: "If you're interested in sausages and charcuterie, you don't ask the pig!"

Glasgow was changing fast as McIlvanney wrote the introduction to Shades of Grey. Oscar Marzeroli's photographs chart those changes. Marzeroli filmed them too, for a short promotional film he made in 1971 – a film edited by Bill Forsyth and called Glasgow 1980. It's a riveting document of slum clearances, industrial decline, and the emergence of a shinier Glasgow. The new and old Glasgows jostle for space in the film as they do in Shades of Grey. What appalled McIlvanney and Marzeroli was not the physical transformation and partial destruction of the city they knew and loved, or not just that, but the loss of a deep-seated sense of community that was flattened along with the tenements.

McIvanney was gobsmacked by the arrival of a new breed of yuppy Glaswegian then swarming into the vacuum: "Where do they come from, these people? . . . no matter how eclectic the gear they wear, what they are mainly dressed in is a kind of hand-me-down self-assurance. They know they're with it because their clothes are with it. They're sure of their identity because they're wearing it." I've seen plenty of their kind over the last few days in Edinburgh (though they tend to dress down now) and McIlvanney might have been talking about them and red carpet events when he brackets them under the rubric "communal pretentiousness."

Funnily enough, I've seen none in Glasgow, despite skipping the Opening Night Gala screening of Jason Connery's Tommy Honour in favour of a midnight-to-six night-on-the-lash with my hospitable Glaswegian friend in the affluent West End. We spent a large part the evening in the amiable, equally hospitable Colin Beattie – a modern patron of the arts and owner of a string of Glasgow pubs and restaurants (including such cherished institutions as the Oran Mor, the Lismore, and the Granny Gibbs). Since arriving, I've been taking a train to and from the EIFF from Partick station as Queen's Street station is being upgraded. Each time I've done so I've smiled at a cheeky statue Colin Beattie commissioned of 'The G.I. Bride' – a character from Bud Neill's 1950s cowboy comic strip Lobby Dosser. In Shades of Grey, William McIvanney writes of his dispirited journeys to and from the Edinburgh Festival (before the Film Festival peeled off on its own and moved from August to July). On one such occasion, a young woman took out a fiddle, began to play, and transformed the train into an impromtu ceilidh: "As we pull into Queen Street, I realise that Glasgow has just had its own unofficial mini-festival."

When the Third Eye Centre canvassed support from the business sector for sponsorship of Shades of Grey, they were frequently told it was too "depressing" and a Mazeroli colour plate book promoting the "new" city was often suggested instead. Outrageously, the book was recently republished – without William McIlvanney's text. Perhaps because he said: "The selling of Glasgow as some kind of yuppie freehold is a diminution of Glasgow." Iain Nairn famously said, "unless the city wakes up to a sense of its greatness, Glasgow is headed for disaster." As long as developers and publishers, the owners of cultural capital and the owners of property, continue to airbrush the city's past from its present it headed there still.