For reasons I was unsure about for a long time, Petula Clark's "Downtown" and Dusty's "I Close My Eyes And Count To Ten" cast the deepest, darkest spell. Back then, I was entranced by the modernist sheen of Roxy Music - by the strange, sensual sway of their slow songs, the sense that they were arbiters of a world of sexual otherness way beyond the dull confines of my own. Somehow, Petula and Dusty - though they came from another time, when sophistication seemed synonymous with melodrama - belonged to that world.

There was a suggestion of repressed desire and deep, dark longings that simmered just beneath the surface of their best songs. I don't know if Petula Clark ever recorded anything else as dynamic as "Downtown," but I do know that Dusty struck out for the stars with the still extraordinary 1968 album Dusty in Memphis; that, in the company of Atlantic Records' finest southern soul men, she finally found an ideal home for her big soul voice. Restrained rather than melodramatic, it remains her finest hour, and its hit single "Son-Of-A Preacherman," her most transcendent moment.

Dusty in Memphis has, over the years, become one of my favourite after-hours albums. Maybe because of her subsequent disappearance from the charts and the various rumours about her (mostly concerning her bisexuality and her Seventies drink problem) Dusty became an almost mythical figure to me; someone who seemed to sum up a moment - Profumo, Ready, Steady, Go!, Mods and miniskirts - then simply faded from view when that moment passed.

Our paths crossed, though, in 1995, when, after a decade of writing about pop music, I had a short-lived career as a pop video director. With my friend Seamus McGarvey, now acclaimed as a cinematographer - he has just shot Tim Roth's The War Zone - I co-directed a couple of videos for a little-known rap group, Marxman. The first illustrated a song about human rights abuses in Northern Ireland and was banned by the BBC for "political bias"; the second, featuring Sinaad O'Connor, concerned slavery and colonialism. They were agit-pop videos, and we didn't land an awful lot of work on the back of them. It was with some surprise, then, that we entered the corporate portals of Sony for a meeting with Dusty Springfield.

To this day, I don't know if Dusty had ever seen either of the Marxman videos; I doubt it. More likely the record company wanted someone with Seamus's talent and expertise to create a video that looked like a feature film. The film in question was Into the West, in which Gabriel Byrne and Ellen Barkin trail two children and a white horse across beautiful Irish landscapes. Our remit was to recreate the feel and look of Into the West for a big, windswept song called "Roll Away". It seemed like a dodgy idea, but it was, for once, a decent budget. And it was Dusty.

For two days, Seamus and I drove around the Galway coast and into County Clare, marking out beaches, dolmens and standing stones on our map. We found a white horse and two children who lived near Cregg Castle, the country house which was to be our base. It was a two-and-a-half day shoot and, since it can rain in the west of Ireland like nowhere else in these isles, we hired walkie-talkies for the crew, ordered pre-packed lunches and tried to make sure that as little as possible was left to chance. We didn't, however, plan for Dusty, who turned out to be a law unto herself.

To put it mildly, she did not trust the video promo process: close-ups, for instance, were out of the question. Neither did she seem aware of the often frenetic pace of video shoots, a momentum that dictates its own creative energy. Not this time, though: Dusty made her daily entrance on set around midday. That is, she left the hotel and made her way over to the 40ft silver Winnebago we had hired at her insistence (making considerable inroads into the budget) from a Neil Jordan film shoot further down the coast. I still have nightmares about that Winnebago: the half-mile tailbacks it left in its wake; the stand-offs between the driver and tractors, lorries and herds of cows. Our schedule went rapidly out of the window.

Then there was the wind: Dusty hated the wind. It blew in off the Atlantic, ruffling her hair and her concentration. Lip-syncs went awry at the slightest gust, and there was talk of constructing a "windbreak" - we explained that, save for a Christo-style wrapping of the entire coastline, there was sod-all we could do about the wind. We shambled along on the verge of panic, shooting what we could where we could.

At the end of the second day, after we had been fleeced by locals who insisted we pay each of them one hundred pounds to film on their beach - which didn't belong to any of them - Seamus and I retreated to a nearby bar. Although not given to overstatement, he explained to me that we were "up shit creek without a paddle".

He had reams of footage of the two kids and the horse, acres of landscapes and sky, but precious little Dusty. Too wired to sleep, we sat up with her until the early hours, trying, but seemingly failing, to impress the need for a change of gear - a half day's total dedication to the delicate art of the lip-sync.

Then, something strange happened. Relaxed by Irish whiskeys, we began quizzing Dusty about her life, about the recording of Dusty in Memphis and what it was like, as a white, second-generation Irish immigrant girl from London, suddenly to find yourself working with Arif Mardin and Jerry Wexler, the architects of Aretha Franklin's southern soul. She seemed remarkably blase about the experience, recounting fragments in her gently self-deprecating way. We were transfixed. Later, before bidding us goodnight, she apologised for the flood of tears that had engulfed her earlier in the day after singing a chorus amid the elemental landscape of the Burren. "I haven't been well," she murmured, "and it all catches up with me from time to time." Little did we know.

The next morning, Dusty was ready on time and, when the camera rolled, she gave it her all, over and over. Ever the diva, she had waited until the eleventh hour, then performed faultlessly, passionately, for the camera. I'm sure there was a mocking twinkle in her eye - a "how could you ever have doubted me?" look - as we all crowded around her after the final run-through, relieved to the point of effusion by her late rallying. She brought out chilled champagne for the crew. Then she posed for photographs, smiling and joking. For a moment, the uncertain, vulnerable human being and the living legend coalesced.

Later, when the rest of us loaded the vans to leave for the airport, she decided, on a whim, to stay on at Cregg Castle to "rest and relax". I remember thinking, as she waved us off, how tired and vulnerable she looked. And how utterly alone.

Dusty Springfield, born 16 April 1939; died 2 March 1999

Sean O'Hagan
The Observer, March 7, 1999