“We're dragging the sunshine up behind us,” says the voice on the phone. “We've tethered it in smaller pieces because with one large sun it's quite hard to drag behind the coach.”

It's July 21 1997, a gloomy day made infinitely brighter by the identity of the speaker: David Bowie. That, by the way, is his answer to my weather-related ice-breaker.

The “we” is him and his band. The coach is the one bringing him north to Glasgow for a concert at the Barrowland Ballroom the following day. It'll be gig 34 on a six month tour supporting Earthling, his so-called drum and bass album, released earlier that year.

Warming to his solar flight of fancy, Bowie ploughs on. “I just read the other day that they've discovered water on the sun,” he says. “Now I can't understand how that works, so you've got to explain it to me, Barry.” Gulp.

Listening to the tape of that interview this morning, as the headlines are dominated by the news of his death from cancer at the age of 69, I laugh at the idea that I could ever explain anything to David Bowie. He, after all, was the one who guided us. A master of disguise, re-invention and assimilation, he took ideas from dance, art, music, literature and street fashion and, across a near 50-year career, fused them into some of the greatest popular art of the 20th century. Throw words like “seminal”, “icon” and “game-changer” at David Bowie and they certainly stick.

Back to the dusty old TDK D90. How does he view his status as cultural icon? The years fall away as the tape unspools and his voice crackles in my ear.

“I'm not really into that,” he says. “What I like to do is try to make a difference with the work I do. I do value the respect I get from my contemporaries but to have Oasis cover my song, to have Puff Daddy cover a song, to have Goldie come along to my gigs - that's where my ego is at. To have my fellow musicians like what I do, that's very cool.”

So does he feel self-conscious doing the older songs?

“Not really because I'm only doing the ones I feel I can get into and which work well within what we're doing at the moment,” he says. “There are some pieces, like The Man Who Sold The World believe it or not, which work well because the re-arrangement I gave it fits absolutely into the idiom we're working in now. But you have to be careful with older songs: if you give them the same treatment they had say 25 years ago, they do sound archaic.”

Then a question I can't believe I ask: is he a dilettante?

“I'm very much an end-of-the-century person,” is his response. “I don't see any boundaries between any of the art forms. I think they all inter-relate completely.” But, he adds: “I'm very good at what I do and I don't turn my hand to something unless I'm very good at it, frankly.”

From there, the conversation bounces around across a range of topics. We talk art (“I like John Bellany's work a lot. He's a good friend of mine as well. A terrific man”). We talk Warhol (“He seemed to be secluded a lot, so it was very hard to get through to him and understand what he was thinking”). We talk fatherhood (his son Duncan, now an acclaimed film-maker, is studying philosophy at university at this point: “I think he'll write,” Bowie says. “I am personally quite happy for him to shape his life any way he wants it to be. Whatever gives him fulfilment is alright by me”).

He also tells me about the Yakuza tattoo he got in Tokyo “one mad evening” a few years earlier - “It features dolphins and frogs and lots of Japanese characters. The tattooist wanted to do it with a sliver of bamboo but I convinced him to use the metal machine. But he brought in all his mates so we had all these strong silent types guffawing around the edge” - and says he's bringing his wife, Somali-born model and actress Iman Iman, to Glasgow. It will be her first visit to Scotland.

“I want to take her to the School of Art. I know it's very touristy but I think she should see some Mackintosh. I'll take her to what's left of the Willow Tea Rooms and all that.”

Did the couple ever get there? Did the Jean Genie sip Darjeeling on Sauchiehall Street? Who knows. But it's pleasing to think he did.

Finally we talk legacy and the ageing process. Bowie has recently turned 50 and his present from Iman was a bound book in which friends old and new had contributed their recollections and fond wishes. “Iggy did a great page in there,” he says happily.

Then a reflection I find quite poignant now, as I try to comprehend his passing.

“I used to think 'Oops I'm getting away with it'. Now I think I'm really good at what I do. The older you get, the more self-confident you get about that. But on the other hand, I think you kind of realise how unimportant it all is actually. So you get pretty ambivalent. I think the priority becomes the day that you're living through. And I think for me, at my age, each 24 hours becomes more and more precious. I hate to get through a day and think that I've wasted it.”

So here's a thing my younger self could maybe have explained to David Bowie: you never did waste a day. You certainly didn't waste a life. And unimportant? God, no. You were a star, man.