The kidney-shaped swimming-pool is clue enough. It has been painted with squiggles so that if empty, it would look full, its surface rippling in the breeze, glinting in the sun. Overhanging it are giant palm fronds and cacti and, beyond them, a pink-walled house with a blue terrace. On this, looking out over the Hollywood Hills, surrounded by chairs and tables painted in egg-yolk yellows and dazzling reds, stands the owner. He has a boyish fringe, a gentle manner, and a soft, quaint, unhurried Yorkshire burr. It can only be… Alan Bennett.

David Hockney is used to the jokes. The two men grew up within eight miles of each other in the West Riding of God’s Own County. Alan Bennett once drew a self-portrait on a napkin for a waitress and signed it ‘Hockney’ and Hockney once signed one of his self-portraits ‘Bennett’. But actually, even at 66, our most celebrated living artist can always be distinguished from his literary doppelgänger by his more flamboyant dress sense. Today Hockney is wearing red slippers with yellow spots, a turquoise watch, checked trousers, blue felt braces and a gingham shirt with a poppy in one of its buttonholes (I brought one over from England for him, to remind him of home).

Inside, in a room with a trompe-l’oeil painted fireplace, a grand piano and floor-to-ceiling bookshelves, there is a three-sided box on a table: a true mirror. ‘Sit down here,’ Hockney says, pulling back a chair. ‘Now look at yourself.’ I do. Unnervingly my reflection is not reversed. Hockney just bought this mirror and it has given him a new impetus to do self-portraits. ‘I usually only draw myself in down periods,’ he says, slowly, ruminatively. ‘I do, actually. I suppose that’s why I often draw myself looking grim. I just think, “Let’s have a look in the mirror.” When you are alone and you look in a mirror you never put on a pleasing smile. Well, you don’t, do you?’

One of the most noticeable things about Hockney is his pleasing smile. It is lopsided, wry, infectious; it makes him seem permanently amused at the world, at himself; and it gives him an air of naive amiability. But, as he says himself, his dreamy bearing has a lot to do with the partial deafness from which he has suffered for 20 years. He can only hear with the help of powerful – and of course, Hockney being Hockney, differently coloured – hearing aids.

There seems to be a lot of activity in the house: Richard, Hockney’s studio assistant, is on the phone; Ann, one of his oldest friends and regular models, is talking to her husband David; there is a photographer and her assistant; a home help; and a dachshund. I ask whether I need to raise my voice. ‘Well we should maybe go up to the studio where it’s quieter,’ Hockney says, leading the way up an iron staircase, past a mobile of day-glo cut-out fish hanging from a branch, and up a path to an airy studio. Here there are easels, pots of paintbrushes, large model hands for drawing practice, numerous paint-spattered armchairs, a treadmill unplugged and gathering dust (Hockney, a chainsmoker, had a mild heart attack in 1990, but now he just swims every day to try and keep fit) and, on the walls, new portraits in watercolour.

‘I can hear fine in here,’ Hockney says, tapping a cigarette out of a packet of Camel Lights. ‘It’s only when there is a lot of background noise that I struggle.’ He lights up. ‘You know, the loss of one sense often heightens another. In my case I felt I could appreciate space much better when I lost my hearing, I think it’s because sound locates you in space. You have to compensate somehow. I am interested in space, me. That’s why I like painting the Grand Canyon. And the Yorkshire moors.’

David Hockney was born in Bradford in 1937, the fourth of five children. He attended Bradford Grammar School, where one of his reports described him as being ‘light relief’. Inspired by the work of Stanley Spencer and Picasso he went on to Bradford School of Art and then the Royal College of Art, from which he graduated with the gold medal. At first his work was quite abstract. Then, in 1963, he travelled to California and developed a Pop Art style all his own – blazing colours, delicacy of line, geometrical buildings painted in oil and acrylic. Bronzed and naked young men by the sides of pools were a recurring theme, but it was the play of light on the water, like strands of spaghetti, that interested Hockney as much as the bare bottoms. A Bigger Splash in 1967 marked the apotheosis of the Hockney technique and, after that, he changed direction and became more naturalistic.

His best-known portrait, Mr and Mrs Clark and Percy, was painted in 1970-71. It was of the fashion designer Ossie Clark (who was later murdered), his wife Celia and their cat Percy. Although out of fear of repeating himself Hockney has experimented over the years with faxing, Xeroxing, snapshots assembled into cubist compositions, and opera stage design, he has always returned to portraiture, playing out his life on canvas by painting his famous friends (Andy Warhol, Christopher Isherwood and WH Auden among others), his lovers and, again and again, his parents, most notably with My Parents, painted in 1977. A collection of these, Hockney’s Portraits and People, is about to be published and, as I flick through the book with him, I note that it amounts to a visual autobiography. ‘The same people do appear over and over,’ he says. ‘I’ve found it easier because I really know them. Portraits are about the relationship of the painter to the subject.’

Do his subjects feel as if they are being immortalised on canvas, given that most of his portraits seem to end up in galleries? ‘I don’t know. But I did once say to Albert Clark, Celia’s son, that he and I had a strange thing in common. We both have a portrait of our parents hanging in the Tate Gallery.’ He draws thoughtfully on his cigarette. ‘I generally don’t ask the subject what they think of what I’ve done. It doesn’t really matter what they think. I’m not out to flatter. That’s not what it’s about.’

Last year he and Lucian Freud sat for each other; what did he learn about portrait painting from that experience? ‘It made me feel more sympathetic towards the people who sit for me. I sat for 120 hours for Lucian; he would only sit for three hours for me. He wouldn’t co-operate, really. Too restless. The difference between us is, Lucian is shy and I’m a chatterbox, except when I am painting. I don’t let people talk when I paint. Well, I don’t mind people talking, but I don’t answer back because I’m tuned out. Lips moving are very hard to get. Actually Lucian and I talked quite a lot when he was painting me. He let me smoke, too, but only if I didn’t tell Kate Moss, who was also sitting for him and who also smokes.’ There is a photograph of Freud’s portrait of Hockney on the studio wall. I ask him if he thinks it flattering. ‘Some people thought he made me look a lot older than I am and I thought, “So what? It’s his account of looking at me, not my account.” Jacob Rothschild, I remember, said, “He’s made you look like a Yorkshireman, David.” I said, “Well, I am a Yorkshireman.” He said: “I mean, as opposed to a painter.” And I said, “Can’t Yorkshiremen be painters?”‘ He gives a throaty laugh. ‘I suppose Lucian would always see me as a Yorkshireman because of my accent compared to his.’

David Hockney does say ‘twenny’ for twenty and ‘liddle’ for little, but otherwise living in California for most of his adult life doesn’t seem to have made much of an impact on his flat northern vowels. ‘It’s because I did all the talking,’ he says. ‘It wasn’t a matter of me trying to retain my identity over here. I’ve never bothered about my accent. When I first went to London, to the RCA, I was mocked for it. People would shout, “Trouble at mill, Mr Hockney?” I used to smile and think, “They have no idea what Yorkshire is like, these people.” Probably my deafness is connected with my retaining an accent.’

Hockney inherited his deafness from his father, Kenneth, who died in 1978. He also inherited a pacifist sensibility, which was why he refused to do National Service and worked instead as a hospital orderly for two years. His father wore two wristwatches ‘in case one was wrong’ and once took his armchair out into the street to wait by a phonebox in case it rang – he had placed an ad in the local paper selling a billiard table and had given out the phonebox number. His father, I say, seems to have been an eccentric; does he take after him? ‘Some of my friends who knew my father say, “You are getting more and more like Kenneth.” He never went out of the house without a hat, a tie and a cane. I suppose he was a dandy of sorts but, later on, he would put string in his boots. He was a conscientious objector, like me, but the big difference between us was, he was ferociously anti-smoking whereas I have always been fanatically pro it. He wasn’t a sophisticated man. He hardly ever left Bradford. He was a member of CND and a socialist with a rather romantic and naive idea of what Soviet Russia was like, all cornfields and ballet. He would have gone mad for email because he was always sending letters to world leaders – Eisenhower, Mao, Stalin – telling them what was what. I think he imagined the Politburo would hold up his letter and say, “Hold everything, Kenneth Hockney has written again!” He was a humble Bradford clerk who was horrified by big bombs. Quite right, too. Mother was in charge. She thought my father rather comic, I think.’

Laura Hockney was a devout Methodist who kept scrupulous ledger books during the whole of her married life. In them she noted every penny spent from the family budget on food and clothing. Has he, I ask, inherited his mother’s caution with money? ‘I don’t know anything about money. It’s always been a by-product of what I do. The moment I could earn a living as a painter I was rich because I was doing what I wanted to do. There was a time when I thought my money was becoming a burden because I just wanted to spend my time in the studio and I couldn’t. I got rid of the beach house in Malibu and now I just have Pembroke Studios in Kensington, and this place. I don’t want any more because I don’t want to look after them. I don’t want paperwork. I’d rather stay in hotels.’

You would need a spare couple of million to buy a Hockney painting – even a roll of his old holiday snaps that were found in Bradford and sold at auction went for £11,000. Does David Hockney know what he is worth? ‘Not really.

No, I don’t actually. I don’t know how I’d add it up. I’m too busy in here to bother, really.’ He shrugs.

‘I never seem to run out.’

Bradford in the 1950s wasn’t a hotbed of liberalism, one imagines. What did his parents think when he came out as gay? ‘They never said anything. They wouldn’t. On the other hand they knew I wasn’t going to take too much notice of what they said about how I lived my life. I don’t know whether I would have been so open if I’d stayed in Bradford. Remember, I lived in bohemia here in LA. It’s a tolerant place. They know about human failings.’ He takes a sip of carrot juice. ‘When I first arrived here it seemed such a sexy, sunny, naked place. California having a climate like it does, people wear fewer clothes. That is why they look after their bodies more. The gay bar scene was big here then. I was amazed. I thought: what organisation! I bleached my hair and felt very free.’

He was promiscuous? ‘When I first came here, yes. It was so easy.’

How promiscuous? ‘I didn’t keep count. It was the only time I was. I remember one very attractive young man who was Mr California Dream. I brought him back with me on a trip to England but I had to send him back to California after a week when I realised he had no curiosity about anything. It was just lust on my part.’ He flicks through the book. ‘I was attracted to California for another reason, though, one which I didn’t realise at the time and that was the sense of space. I’m claustrophobic, you see. Also the climate attracts you. It’s 20 times brighter here than in London. I don’t think the people here really appreciate what they have. It sometimes takes a foreigner to come and see a place and paint it. I remember someone saying they had never really noticed the palm trees here until I painted them.’

At one stage he seemed to become almost as well-known for his flamboyant dress sense – the wide-brimmed hats, the peroxide hair, the big owlish glasses – as for his paintings. Was this just vanity? ‘All young artists know that somehow you have to attract attention to get people to look at your pictures. My vanity as an artist is that I want the pictures seen.’

That sounds quite cynical. ‘I didn’t wish to be a celebrity. I just wanted to be an artist. It was always about the pictures.’

When, in 1966, he met Peter Schlesinger, a good-looking young student, his years of promiscuity came to an end. ‘That was my first long-term relationship,’ he says. ‘Isn’t that what we are all looking for? My relationship with Peter lasted for five years.’

Schlesinger was the subject of some of Hockney’s best-known paintings. Was he the love of his life? ‘Not quite. Peter wasn’t as keen on music as I was. Think I took him to too many Wagner operas. I suppose if you are not that keen on music, Wagner must be a big bore… I have a relationship now…’ He turns and points to a portrait on the wall of a young lantern-jawed man. ‘But John is stuck in England. They wouldn’t let him back in because he stayed two days too long last time. I’ll get him back.’

Is Hockney difficult to live with? ‘Well, you do have to be selfish as an artist. Painting is a solitary activity. I like people, I’m just unsocial because of my hearing, not antisocial. My sister pointed out that a lot of my paintings have a lot of loneliness in them. Empty chairs. She did. She pointed that out. I thought, “That’s a good interpretation, actually.”‘

There have been many interpretations of Hockney’s work, I say. One thinks of Sur la Terrasse, which shows Schlesinger turning his back on the painter as their relationship came to an end in 1971. Does knowing the narrative behind a painting help appreciate it? ‘I don’t think so. Everything after a while becomes decorative, which is why you are not moved by looking at a crucifixion picture in the National Gallery. You are looking at it as art, at its formal qualities.’ He licks the corner of his mouth, a tic of his. ‘With Sur la Terrasse I could just have been thinking, “Doesn’t he look cute from the back?”‘

He closes the book and, looking over his glasses with clear blue eyes, says, ‘Do you want to know what moves me?’ He fetches a photocopy of a Rembrandt sketch showing a group of people helping a child take its first steps. ‘I think this is the greatest drawing ever made by anyone. It’s a very ordinary subject which any viewer has experienced and observed. Think how fast his hand must have been moving when he did this. Look at the way this woman’s head is tilted so you can see her expression. Look at the weightlessness here. I think this is far superior to the Mona Lisa.’

Rembrandt’s skill clearly affects him but what about the subject matter? Does he wish he had had a child he could teach to walk? He flicks his cigarette butt on to the studio floor and stubs it out with his slipper. ‘I did see a child learn to walk. Albert Clark. Perhaps that is why I find this so moving.’

Is it true he had an affair with Clark’s mother, Celia? He purses his lips. ‘It was never that serious. I would have liked to have had children. I think about that a lot. As a present to my assistant, Richard, I paid for him to have his vasectomy reversed so that he could have children. And he did, too. And is very happy. I used to look at my brother [who is Hockney’s accountant, and a former mayor of Bradford] and his children and think he had it all wrong.

I thought, “How conventional of him. What is all the fuss about?” Now I don’t.’

Because he’s older? ‘I was with my mother on her deathbed four years ago. It made me think.’

Did he paint his mother then, as Monet painted his dying wife? ‘I did, as it happens.’

Wasn’t that cold of him? ‘It’s what an artist does. It’s how an artist responds to the world. I suppose it was a way of dealing with it, or not dealing with it.’

He has had to deal with a lot of grief in his life. ‘At one point I was flying weekly to New York where I had four different friends dying from Aids in four different hospitals. I lost a hell of a lot of friends. That is why New York is so different now. Two generations were wiped out, really. Very talented people.’

How many friends did he lose? ‘A lot. Friends and acquaintances. I couldn’t write it down, I must tell you. I once tried but I couldn’t do it, it drove me mad, actually. I got to the point where I didn’t even want to answer the phone in case it brought more news of premature death.’

Does he feel lucky to have survived?

On one level a studio high up in the Hollywood Hills seems exactly the sort of place to encounter one of Quentin Crisp’s ‘stately homos of England’. Hockney seems at home here, comfortable in his skin, at ease with the Californian banality. His language, like his paintings, like the primary colours his house is painted in, seems simplified. And he has a childlike candour and curiosity. He loves gadgets and mirrors and cameras (as he demonstrated in his bestselling book Secret Knowledge, in which he showed how the old masters had used a camera lucida for their portraits).

‘I never had any self-doubt,’ he tells me at one point in the studio on the hill. ‘But there were times when the art world would say, “What are you doing wasting your time on photography?” Of course I didn’t see it that way because I was finding things out.’

Hockney is unassuming about his work. And his wit is as dry as a Yorkshire stone wall. When I ask him about his enduring popularity – the critic Robert Hughes once called him ‘the Cole Porter of contemporary art’ – he smiles and says, ‘Sometimes there is a prettiness to my work. I can’t help it. I can’t help putting the charm in.’ And later, when I ask him which place he regards as home, Yorkshire or California, he says without missing a beat, ‘I’m a Yorkshire Californian.’

‘Let me show you something,’ he says, leading the way back down to the house. When we reach the door, he stops and adds, ‘Wait here.’ He disappears inside and, when he re-emerges, I follow his tall and stooping figure along a corridor. ‘Now, look at that,’ he says. Through another doorway I can see a mirror which is reflecting a predominately red painting of a village on the opposite wall, out of sight. It looks three-dimensional. ‘Amazing what mirrors do, isn’t it?’ he says. ‘That’s Sledmere in Yorkshire. I painted it in 1997 when a friend of mine, Jonathan, was dying of cancer in Wetherby. I would visit him every day from Bridlington, where my mother was, and I kept driving through this village. I want to go again to paint Yorkshire next year. Yorkshire is like the American West because you can see a long way. I like that, seeing a long way.’

J.

James Blunt

It could be the homes around the world; his military bearing; or that he’s our biggest musical export since Elton. For whatever reason, being called annoying, a philanderer or – worse – middle class doesn’t exactly keep James Hillier Blount awake at night. Nigel Farndale met him

It’s not the sight of the groupies that haunts me, but the sound, or rather the absence of sound, as they ghost past us on their way up the stairs to the dressing-room. It takes me a moment to figure out that the reason they aren’t talking to each other is that they don’t know each other. One of the band members, the keyboard player, I think, has picked them from the audience on the basis of their looks. Half-a-dozen of them, all in their late teens and early twenties, and all, surprisingly, in pretty frocks, as if they were going to a Sunday school meeting. They have been separated from their friends like lambs weaned from their mothers. The silence of the lambs.

The ‘us’ they are filing past is James Blunt and me. He has a bottle of beer in one hand, a cigarette in the other, and not a hair in place – tousled just so, like a Renaissance painting of John the Baptist – but they don’t realise it’s him because he has changed out of the suit he was wearing on stage and is now in jeans, T-shirt and leather jacket, as well as a pink feather boa and star-shaped novelty sunglasses. But I’m getting ahead of myself. This is the end of the day; we need to go back to the start, well, to the middle, when the seats are empty and the Texan sun is at its most unforgiving.

A barefoot and unshaven Blunt is wearing normal sunglasses and shorts as he plays his piano, strums his guitar and sings his plaintive songs into the microphone for the sound check, all the while looking out with his soulful eyes over an empty, open-air arena in Houston. At 5ft 7in, he’s not a tall man, but he has presence and an unaffected manner – a certain maturity, too, one that you wouldn’t normally associate with a pop star in the ascendant.

But then he is 34 and this is his second career, his first being as an officer in the Household Cavalry. He joined after graduating from Bristol University with a degree in sociology. He became a champion skier for the Army and not only saw active service in Kosovo, but also guarded the Queen Mother’s coffin when she was lying in state.

Tonight he will be supporting Sheryl Crow, though, since his second album ‘All the Lost Souls’ and the single from it, ‘1973’, went straight to number one in America, he is arguably the bigger act these days. Indeed, not since Elton John has there been a more successful British singer-songwriter in the States.

His first album, ‘Back to Bedlam’, also went to number one over here, as it did in 18 other countries, making it the biggest-selling album of the millennium. It even entered the Guinness Book of Records as the fastest-selling album in one year. But it was his first single that really put him on the map. You’re Beautiful became the sound of that summer. It was everywhere, and still is – having become a favourite at weddings, funerals and bar mitzvahs. I even heard a brass band playing it at an agricultural show in the Yorkshire Dales this summer.

As well as millions of sales, James Blunt has won Brit awards, Ivor Novello awards, MTV awards and various Grammy nominations. In terms of credibility, he’s headlined at Glastonbury and won the respect of the world-weary music press. Yet not everyone loves him, as he points out when we get something to eat in the canteen area back stage.

‘After Back to Bedlam really started selling,’ he says, ‘there was this sudden aggression towards me in the UK, for whatever reason, and that focused my mind, made it clear to me what I was doing and why I wanted to do it. I write songs for myself. I don’t write them for you, or for anyone else, I write them because I have experiences that I need to process. I don’t have the answers all the time, but I do have lots of questions, and I express them in the songs I write.’

He is, I think, alluding to a poll last year of ‘the most annoying things in life’, which put him at number four, just behind cold-callers and queue-jumpers. ‘I haven’t met anyone who voted in the poll, have you?’ he says when I mention this. ‘That poll probably came from a website that was after some publicity. You and I could do the same poll very quickly right now and it would count as a poll. We could do one about annoying newspapers, for example. I promise the Sunday Telegraph wouldn’t be in my list. My parents take it.’

His father, a retired colonel in the Army Air Corps, manages his son’s finances. His mother arranged the purchase of his six-bedroom villa in Ibiza (he also has a chalet in Verbier and recently bought a place in Chelsea). ‘I’m not married,’ he says, ‘and so the support structure in my life is my parents. I’m closer to them now than I have ever been.’

He certainly isn’t married, as the photographs of him emerging from nightclubs with various high-profile women on his arm attest. Tara Palmer-Tomkinson was probably the best known socialite, Jessica Sutta, of the Pussycat Dolls, the most glamorous. He also seems to be photographed regularly cavorting on beaches with bikini-clad models such as Petra Nemcova, whom he dated and then dumped – unceremonious dumping being his way of ending relationships, according to the tabloids. He once said he found himself in a swimming pool in LA with nine naked women. ‘I was the only bloke. It was the only time I wished my mates were there, purely to spectate. I had arrived. It was a moment.’

Now he says of the tabloid interest in his peripatetic love life: ‘Last week I went to my home in Ibiza and was photographed by the paparazzi in my swimming trunks with girls. What is the point of that? I’m not that bothered, but maybe the media should be concentrating more on global warming or the Russian invasion of Georgia.

‘Looking at me in my swimming trunks is not a great sight. It’s a waste of time. There generally is a long lens pointing at me wherever I go, these days. I’m comfortable with it. I appreciate how things work. But my record label said something about my always being photographed coming out of nightclubs and I thought, “But this is what I do. I was doing it before the second album came out, so what is different now? You didn’t tell me to stop then.” I’m not going to change my life because of these people. I don’t see why I should.’

His label also gets him to dye his grey hairs and be enigmatic about his love life, which is an old tactic dating back to the Beatles – they had to pretend they didn’t have wives and girlfriends so that fans could fantasise they were in with a chance.

Actually, at the time of going to press, Blunt seems to be going out again with one of his old flames, Verity Evetts, an Oxford-educated barrister. He has also stayed friendly with some of his other exes, the socialites at least. He told one – an ex who got married not long ago – that he doesn’t feel ‘centred’ at the moment and would like to get married as well. Then again, he also said that he never tires of singing You’re Beautiful night after night because it gets him laid night after night.

Either way, he tells me he has grown used to the idea that his mother will probably find out from the papers what he has been up to, and with whom, before he has had a chance to tell her. ‘And my [two] sisters are quick to email me about things in the papers, laughing their heads off. I get healthy, ritual abuse from them, and give it back myself.’

As we are talking, I can’t decide whether the way Blunt smiles all the time is disarming or disturbing. He’s like a victim of a religious cult, smiling at the beginning of the sentence and at the end. I guess he has a lot to smile about, but also I sense a great deal of insecurity to disguise.

Then, I’m distracted by the sight of Sheryl Crow playing table tennis across the room. She has been holding her adopted son in one arm as she bats with the other, and now, even more distractingly, she is heading straight for us. ‘Are we going to have one of our little conversations on stage again tonight, James?’ she says. ‘That flirting thing. I think it worked well last night.’

They discuss the duet they will sing – a cover of Cat Stevens’s The First Cut is the Deepest – then we both watch her shimmy away, her blonde curls bobbing. ‘She’s very down to earth,’ he says. ‘I’d met her a couple of times, which was why she asked me on this tour. We do end up playing a lot of table tennis on the road. We’ve done 117 shows so far this year, in 117 cities, and there are a lot of hours to fill in the day.’

As he sleeps on his tour bus with his band, one city tends to blur into another. When I joke that he is in Cincinnati now, he looks genuinely confused. ‘No, this is?… Oh, right. Actually, I always get the tour manager to say where we are just as I’m going on stage. I still managed to get it wrong the other night, saying “Hello Dallas” when I meant Austin. I’m surprised I got out alive.’

He is funny on the subjects of things that go wrong. ‘People are normally surprised by my show, which is more energetic than you might think. Jumping on the piano. Jumping out into the audience and running up and down the aisle high-fiving them. But going off the stage can be quite dangerous. I broke my finger once. My legs carried on when I jumped off, and I smacked down on the ground. The spotlight was on me, and when I got back to the piano I hit the wrong note and thought, “Why did I do that?” And I looked down and saw it was because my finger was broken, sticking out an angle. Look,’ he says holding it up. ‘It’s still crooked.’

On another occasion, in Chicago, he jumped 8ft off the stage. ‘When I began running to the audience, a security guard stuck his arm out and I thought, “Does he want a hug?” Then next thing I know he’s rugby-tackled me. He wouldn’t release me and I was screaming in his ear, “I’m the f—ing singer.” I had to wait for the other guards to pull him off.’

I would have thought Blunt’s training in unarmed combat would have helped. I presume he still works out. ‘No, never. Couldn’t handle it. Too boring. I am a hyperactive person though.’ He likes an adrenaline rush, as well, having recently bought an 1100cc Moto Guzzi V11 Sport motorbike. There’s also the skiing, which he still does, and the riding. Actually, he tells me, he never really liked horses before joining the Life Guards. So why did he join that particular regiment?

‘Well, it is a reconnaissance regiment.’ But they are all so tall in the Life Guards, did that not make him self-conscious? ‘Some are. The Foot Guards tend to be taller regiments, though. The Life Guards take a few shrimps, as well. Besides, they are on horses, so height isn’t so important. Also being in that regiment had the benefit of being in Knightsbridge. I got a chance to be in London and meet people in the music scene.’ And groupies, as it happens.

As he paraded up and down the Mall in plumed helmet and shiny breastplate, girls would stick their phone numbers down his knee-length boots. But it was his time in Kosovo that really made girls swoon. He used to strap his guitar to the outside of his tank, because there wasn’t room for it inside. He had learnt to play the violin at five, the piano at seven and the guitar at 14, while a pupil at Harrow.

He writes his songs on piano and guitar. ‘But mainly guitar because it is easier to carry around. It’s like a child messing around with a toy. If a tune comes to me I don’t record it instantly. I think if I remember it, then it must be worth remembering, and if I forget it, then it was forgettable.’

Does he have any anxiety dreams about forgetting lines or chords? ‘Not yet. Perhaps I will tonight. Perhaps you’ve jinxed me. But audiences aren’t judgmental, and if things go wrong and you can look them in the eye, that is fine. The only people who are judgmental are the journalists. I will be conscious of you being there in the audience judging me.’

Blimey. Sorry about that. Is it true he signs breasts? ‘Not that I remember. Not that I’m fussy what I sign. A lot of men started coming to the shows after I appeared on Top Gear last year. That was such fun. I spun the car five times. I thought I might as well make the most of it. I am competitive.’

He recorded one of the fastest laps, but I’m surprised blokes didn’t think him manly before that, given his tour of duty in Kosovo. ‘It’s because I sing songs that are heart-on-your-sleeve and therefore I must be overly emotional. Nothing I can do about it. I could pose more, but I am comfortable with my masculinity.’

He has said that his lyrics are autobiographical, in which case, are we to assume that the lyric on his new album, ‘I killed a man in a far away land’, means he killed a man in a far away land? I only ask because in the past he has said that he would never try to exploit what he went through, what he saw. ‘You should ask any soldier how many lives he has saved. How they do it is no one else’s business. What I took from my experience in Kosovo is that you are told from one day to the next who your enemy is and it keeps changing. That’s what is happening in Iraq, too. I believe in looking people in the eye, looking for the common humanity.’

He is a great believer in looking people in the eye. He will use the phrase again later and it seems to reveal a Christ complex, or a John the Baptist one. That direct and challenging stare of his. It would also explain the hair.

It is time for him do some photographs before he goes on stage and, endearingly, he says he is ‘not fussed’ about the grooming he is offered before they are taken.

On stage his features contort with passion when he sings. The big video screen goes in tight on his face. His voice is by turns soft and tremulous and forceful, but always high. Having seen him in concert once before, a couple of years ago, I notice the tone of his banter has changed.

‘Wow it’s hot tonight,’ he says now. ‘I’m surprised any of you are wearing any clothes. We could all take them off and get friendly.’ It is suggestive, designed to get the teenage girls in the audience screaming. Before he used to joke about his ‘girlie voice’ and taking helium to get it that way, and being ‘a bit wet’ and the ‘housewives’ favourite’. I think now he has realised that, actually, he is a proper musician, a popular one, too, and that he doesn’t need to apologise for it.

Afterwards, back in the dressing-room, he strips to the waist as he talks because he wants to take a shower before going back on to do his duet with Sheryl Crow. ‘Things got a bit hairy out there when I jumped into the crowd,’ he says. ‘Did you see that? Some thought it was some kind of sport to grab me.’

I watch his duet from the side of the stage and notice he whispers something in Sheryl Crow’s ear and then she starts running her hands over his trousers suggestively, patting them. Afterwards, I ask what he said. ‘”Is now a good time to ask for your phone number?” She was checking my pockets, pretending to look for a pen.’

He shows me round the gold-coloured tour bus where he will be sleeping tonight as they drive to their next gig in Dallas. It is full of hi-tech equipment and is nicely air-conditioned but there isn’t much space in the bunks. ‘We do live in close proximity,’ he says. ‘Some of us stay up late. This is the crew end, they have to get up early.’

Where do the groupies go? ‘Never have groupies on here. Never. They’d only get in if we invited them in. But we’d only ever invite friends in.’

Does he sleep OK? I heard he has to take sleeping pills. ‘It is a bit of a rough sleep, but better than a hotel and taking planes all the time because you have to get to the airport two hours early, which is miserable. Then your flight gets delayed.’

He is drinking champagne from a plastic cup. ‘This is for your benefit,’ he says. ‘The tour management went out and bought a bottle of champagne because he thought I should be seen drinking it. Better for my image. Isn’t that sweet? Normally, we drink vodka and beer. In fact, I think I’d rather have a beer, now. Want one?’ He opens a well-stocked fridge then takes me to the back of the bus where there is some seating space. He has one small case which he pulls out from a cupboard. It continues a few pairs of socks, T-shirts and a spare pair of jeans. No photographs or mementos. ‘This is all I have for 14 months on the road,’ he says. ‘I’m not known for style.’

Does he know how much he is worth? ‘No I don’t, not very interested in it to be honest. I travel with hand luggage only. That is why I always seem to be wearing the same clothes in photographs. If a tabloid says my clothes aren’t fashionable or my hair looks stupid, I really don’t worry about it. Don’t have any hair gel.’

In London, he takes the Tube or the bus. He prefers pubs to restaurants. When he goes to Ibiza, he flies easyJet. Still, that’s at home. Presumably on the road he can afford to be more self-indulgent.

Another lyric that we can only assume is autobiographical is ‘I’ve taken a s—load of drugs’. It is. Though his only comment on the subject is that he has ‘a comfortable relationship with drugs’. His relationship with fame is less comfortable. Oscar Wilde said there were two forms of tragedy: not getting what you want, and getting it. Is that how it felt for him when he went to number one? ‘Actually, I don’t think I had been dreaming about it. Certainly, I hadn’t anticipated being so recognisable so quickly.

‘I do remember getting a phone call from the record company, who said both the single and the album have gone to number one, and thinking, “S—, this is not what I expected.” I hadn’t prepared myself for it. Number two is great. Number two is nice. I sensed then it would mean having to change from being a musician to being a celebrity and that that would be a change for the worse. Fame doesn’t affect me, but it does affect everyone else around me. As for celebrity, it is the worst invention of the modern world. Gossip columns treat your life as if it were a cartoon. Relationships reduced to cartoons.’

Although there are other public-school bands around at the moment – Radiohead, Coldplay – Blunt seems to have suffered more than most from a perception that he is too posh to be credible. His family name is Blount (and his middle name Hillier), but he changed it to Blunt to sound, well, blunter and more proletarian.

When he tells me he would nevertheless still send a son of his to Harrow – ‘I think I would. I think I would. Public schools make individuals rather than sheep’ – I ask what he makes of the mood change now that the old Etonian David Cameron has made it OK to be posh. ‘Is it? I must come back to Britain immediately. Is it really safe to come back?

‘It’s not a dirty word to be posh, people come up to me and no one gives a damn if I’m posh. It’s about having a normal conversation and looking people in the eye.’

We head back to the dressing-room where he puts on his feather boa and novelty sunglasses then we wander back downstairs to have a word with Sheryl Crow, who is signing autographs. This is the moment at which the keyboard player says: ‘This way to the good-time room girls’ and the silent groupies dutifully appear.