To call it a split personality would be to overstate the case, but there is a measure of contradiction pulsing through Yusuf Islam’s character. I see it when he arrives for a photographic shoot at Leighton House, near Holland Park in west London.

The gallery has been chosen as a setting because of its Arab hall – an appropriate backdrop for Britain’s best-known Muslim convert.

Although he was born in London 58 years ago – and raised in the city, too – it is Islam’s first visit here and, as he maunders around the hall, examining its Islamic tiles, he looks like an Eastern mystic: serene and greybearded in a kameez shirt, his hands forming a fig leaf behind his back; he is nodding to himself and silently mouthing translations of Arabic phrases he reads on the walls.

But when the shoot begins and he is asked to sit on the mosaic floor, he shakes his head. The temperature changes. He has become the veteran pop star once more, aware of his image, used to getting his own way. He doesn’t want to look ‘hunched up’, he says, holding up his hand to silence any objection.

The song You’re So Vain by his one-time girlfriend Carly Simon was said to have been written about him. Then again, it was said to have been written about a lot of Seventies rock stars. ‘Vanity was one of my problems,’ is all Yusuf Islam will say on the subject now.

He pointedly uses the past tense – was – to refer to the days when, under the name Cat Stevens, he sold more than 60 million albums, experimented with drugs, flew all the way to Washington just to get his teeth capped, and, in the memorable phrase of one of his associates,‘wasn’t exactly celibate’.

The present tense is for what happened after 1977, the year he turned his back on the music industry and the hedonism that came with it, renouncing both as sinful. He auctioned his guitars and gold records for Islamic charities.

He even wrote to his record company and asked it to stop selling his albums (it refused). More significantly, he changed his name and dedicated himself to founding Muslim schools in north London – four of them to date.

‘There is a cultural difference between what I represented as Cat Stevens and what I represent today as Yusuf Islam,’ he says carefully, with a trace of London in his vowels. He says everything with care and films himself saying it.

There is a small microphone strapped to his arm, its neon light glowing, and it is wirelessly linked to a video camera he has placed in the corner of the room. He seems earnest, sincere and defensive.

He has good reason to be. In 1989, he was quoted as saying that, according to a literal interpretation of the Koran, the fatwa on Salman Rushdie was understandable, sort of. A media storm broke and he claimed he was misquoted, or at least his meaning was wilfully misconstrued. He has recorded his every public utterance since.

His manager – with a new album, his first in 28 years, his career needs managing once more – comes in and says that his man doesn’t want to answer questions about Iraq, which might seem a little eccentric, given that Yusuf Islam is a pop star.

But I know what he means. Whether he likes it or not, Islam has been cast in the role of unofficial ambassador for Britain’s two million Muslims, and in recent years that has not been the easiest gig in the world.

On the CD box of his new album,‘An Other Cup’, his former stage name is, perhaps with some weariness, acknowledged on a sticker. He can’t get away from it, it seems.

But even if it wasn’t there, you would know straight away it was Cat Stevens you were listening to: a semitone lower, but the same folksy, fluid, easy-going vocals and acoustic guitar patterns – a patina familiar from songs such as Moonshadow, Father and Son, Peace Train, The First Cut is the Deepest and, that staple of school assemblies, Morning Has Broken.

Cat Stevens has a long and impressive back catalogue, so long and impressive that it has kept him in royalties for life. As with his name, the old songs just won’t go away.

On the morning I meet him he has just been told that Wild World (‘Oh, baby, baby it’s a…’ – that one) has re-entered the Top 40 because teenagers have been downloading it onto their iPods, the song having just featured on a youth television programme.

His Tea for the Tillerman, meanwhile, has re-entered the collective consciousness thanks to Ricky Gervais: he uses it as the theme tune to Extras.

The ‘why now after 28 years?’ question meets with a sweet answer. He and his wife, Fauzia Mubarak Ali, the daughter of a Surbiton accountant, have five children. One of them, his 21-year-old son Muhammad, brought a guitar into the house and started writing songs on it.

Islam had assumed that his religion frowned on music. ‘But my son helped me come to a better understanding of where music sits in Islamic culture and I found myself free to sing again.’

So there was no taboo about it, after all? ‘My son broke the taboo for me, because he had no hesitation in buying a guitar. He is a Muslim, too. It made me realise again that music helps us to share moments.’ He nods thoughtfully.

Islam had planned to make a one-off return to music in 1985: he was lined up to play at Live Aid but – tuh! – Elton John over-ran and he was squeezed out of the schedule. Had he not even been singing to himself in the shower in all that time?

‘No, no, no. I really walked away from the business. It was a statement in a way because I felt a kind of rejection from the media the moment I adopted a new name. They didn’t really want to know me. They wanted me to remain as I was. When I received a cold shoulder at this turning point in my life I felt: well, if you don’t love me then maybe I don’t love you.’

He didn’t love himself much either, presumably, given that he had changed his identity in such a profound way. ‘I got to the point, like many a pop star, when I thought the world rotated around me. Islam put me in a spot where I realised I had to bow to a higher power and simply dedicate myself to living properly. Without guidelines that is difficult to do.’

His conversion occurred after he nearly drowned off the coast of Malibu in 1976.A strong current was pulling him out to sea and, having no strength left, he said, ‘God, if you save me, I’ll work for you.’

At that moment, a wave came and he was saved. When I ask him how he was sure it was Allah who had answered his prayers and not the Christian God of his Catholic upbringing, he smiles and says, ‘There is only one God.’ He had been reading the Koran at the time.

A coach party of 25 people turns up at the gallery so we walk to a nearby café – and, as we do, Islam is recognised by a Muslim man who wants to shake his hand. He gets that a lot, he says. He always feels at home in cafés. His father ran one in Soho.

Born Steven Demetre Georgiou, he was the son of Stavros, a Greek- Cypriot, and Ingrid, a Swedish Baptist. When Steven was about eight years old, his parents separated, but both continued to run the restaurant and live above it.

Islam says he was forever trying, and failing, to reconcile them. His father was known as ‘Belos’ – The Mad One – because he had a short temper.

Was the appeal of Islam for him partly paternalistic? ‘Yeah, but there is a central dimension to Islam which a lot of people don’t see. They see the external, which can look paternalistic, but there is an internal perspective of knowing your Lord. I don’t think any prophet ever came except to connect people to the one Lord. Once you see there is only one Lord then you realise you are not the boss, you have to serve.’

You learn humility? ‘Humility. Exactly. Not often associated with pop stars. That is the character change I had to go through. For that reason, standing on stage in front of 40,000 people did not suit me.’

He didn’t enjoy the applause? ‘Some introverts overcome their problem by exhibiting themselves publicly. I think Jimi Hendrix was the same. He was a very shy person. Mmm. To know him, he was a very gentle speaker but his image required him to be a big personality.’

Cat Stevens toured with Hendrix in the late 1960s. Hendrix, indeed, had helped him overcome his stage fright – he gave him a pint of brandy mixed with port to drink every night before he went on.

Does he ever shake his head at the thought that he hung out with Hendrix and somehow survived? ‘Yes, well, that was one of the strange things. There was a lot of clubbing and drug-taking going on. But it gave me an insight: that whatever happened on the outside of showbusiness, there is an inner journey that you have to take as well.’

Or you end up dead? ‘There was a flurry of rock-star deaths at that time and their names all seemed to start with J: Jim Morrison, Jimi Hendrix, Janis Joplin… then I went and chose Joseph as a name! Luckily it is the Arabic pronunciation, Yusuf. There was a time when I did wonder what was going on. I was a victim of it too, in a way, because I ended up in hospital for months with TB, in a convalescent home in the middle of Surrey. I had lost control. I was forced to step back and think.’

Fame and fortune had certainly come to Cat Stevens at a young age. He was only 18 when he had his first hit, Matthew and Son, in 1967. Did he feel like an impostor?

‘Suddenly, I was having to find my own identity while being put on a pedestal; people were forging my identity for me as I went along. I felt lost and unfulfilled. I didn’t know who to listen to. The only role models I had were other pop stars. And chart success is a fleeting delusion.’

All the songs on the new album are written by him, apart from one, a cover of the song made popular by Nina Simone and then The Animals: Don’t Let me be Misunderstood. ‘Yes, I do feel misunderstood and not just in the Muslim phase of life. It was partly my fault because I was looking for my identity. I was afraid of being misunderstood.’

Even before he became a Muslim, though, journalists found him heavy-going intellectually. He complained of being ‘misinterpreted’, but it may have been more a case of interviewers being baffled by his opaque pronouncements about everything from Maoism to UFOs.

He does tend to get a little tangled in his thoughts, and I have untangled him in places here. The biggest misunderstanding was over Salman Rushdie.

‘I was pretty green; I had no idea what kind of traps were being laid for me. Rushdie was never my subject. And people tried to make it my subject and I feel offended, deeply offended because of that… I just wanted to enlighten people as to what I had learnt from the Koran in my research; this as far as I could see was what the Koran had to say on the subject, but then I got tagged with something completely different.’

He was more than just misunderstood in 2000, when he was denied entry into Israel for allegedly making donations to Hamas, something that he strenuously denies and which was never proved. Four years later, he was en route to America when his name came up on a ‘no-fly’ list; the plane was diverted to Maine.

‘Wait a minute!’ he thought, as he sat in front of three FBI agents in the US immigration office. ‘Am I supposed to be the baddie?’ Yes, was the answer as far as the FBI was concerned. The following day, Yusuf Islam was deported back to Britain.

He still hasn’t been told why he was on a no-fly list, but he assumes there was a mix-up of names and identities. It provoked a small international controversy and led the Foreign Secretary, Jack Straw, to complain personally to the American Secretary of State Colin Powell at the United Nations.

Powell responded by stating that the watch list was under review. Yusuf has since been allowed back into America.

It sounded like he was a victim of religious profiling, but does he blame people for feeling nervous when they see bearded Muslims on planes? ‘Even I get nervous when I see someone with a beard! If I don’t know who that person is. It’s true that some look a bit frightening. Some of these people, I know them, they look ferocious. The beard happens to give a masculine look, a more virile appearance, but what goes on behind it, well, I’m an example, if you listen to my music. Yes I had a beard as Cat Stevens but now I have grown wiser and my beard is longer.’

Is it true that American airport security personnel asked for his autograph? ‘So many people do, even Cherie Blair. I was in Downing Street with a number of Muslim delegates and scholars and she was so excited to meet me because my music had had an impact on her.’

What advice does he give on these occasions? ‘I would say the age of reason hasn’t ended and for every effect there is a cause. I suppose even for the Task Force Group who looked into what might have ignited 7/7, it comes down to a common agreement that foreign policy had an enormous amount to do with it.

‘It has nothing to do with ordinary Londoners in the street, it is to do with governmental attitudes abroad. We all suffer from that. The Government is suffering from that, too, because of a misinformed adventurous approach to security, when in fact security can be solved quite easily with a little more attention to the injustice to Muslims continually perpetrated around the world.’

As well as with the Prime Minister, he has also had meetings with Kofi Annan and Prince Charles. He doesn’t like being seen as a spokesman for British Muslims, but can he see why, given the current religious tensions, people might want to know his views?

‘A person like myself, who has been brought up in the West and lived most of my life aiming for the same goals that we all do in this society, and, having achieved them, discovered they were still not fulfilling and then finding Islam…’ The answer drifts away.

‘Because of the extremes that some people have gone to, on both sides, of wanting to start wars and polarise the world into two camps, and I think the natural instinct of humanity is to come to a balanced position after a while.’

Does he feel he has been a victim of Islamophobia? ‘Yes, exactly. What happened on the plane. Islamophobia affects me directly because Islam is my name, Yusuf Islam. Then came the bad news.’ He refers to 9/11.

‘That took over the headlines and allowed people to define Islam politically. They are using the wrong dictionary, the dictionary for Islam is a spiritual one, and it’s a harmonious one, a universal one.’

I suppose the trouble is that we didn’t really think about Islam much in the West until 9/11, when we were… He finishes my sentence: ‘Forced to think about it.’ Exactly, I say, and one thing we were forced to think about was where the loyalties of British Muslims lay.

‘I think the loyalty question for British Muslims doesn’t matter; being British doesn’t mean you can’t be a believer. I do find it very strange that it tends to be liberals who argue with you that you have no right to believe anything different from them.’

He laughs, a slow bubbling laugh. ‘To me, what I found in Islam was it contained scientific reason, along with spiritual reality. It is only when those things are distorted that people disagree.’

Does he feel his religion has been hijacked by extremists who don’t represent what he thinks? ‘There are extremists on both sides who are determined to create conflict, and so they have missed one of the great messages that Islam contained peace in its own name: salaam. Islam.

‘That is one of the first things I learnt as a Westerner. Oh my god, that’s interesting, didn’t I write a song called Peace Train? A Muslim roughly translated is someone who has made peace with God and who has learnt to live with others.’

The 7/7 suicide bombers described themselves as martyrs in their ‘martyrdom videos’. Does he think they were martyrs? ‘This is not my subject, but the Koran forbids the taking of your own life in clear, categorical terms.’

So they didn’t go to heaven? His tone changes at this question, takes on a harder edge.‘I’m not a judge, and neither are you! That is the wrong kind of question to ask someone who has a record of wanting peace.

I want to communicate that peace. I don’t want to be entangled in the confusion in your mind or other people’s minds about what Islam is. Let me speak clearly from my heart. Let me express myself through my music.’

Fair enough, Yusuf. Fair enough. Is it going to be another 28 years before his next album? A grin. ‘I believe I have a few more good songs in me yet.’

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.