In a cavernous concert hall on the outskirts of Rotterdam, Neil Diamond stands centre stage, bathed in a deep blue light. With music murmuring quietly behind him, he tells the tale of how his grandmother made a gruelling journey by boat to New York in 1912, and how she had begun her voyage in this Dutch city. He puts his hand on his chest, the lights turn pink, and the background music swells into "America", one of the many hits from his vast oeuvre. As he sings the opening lines – "Far/ We've been travelling far/ Without a home/ But not without a star" – Diamond tilts his chin upwards and hoists his fist into the air like the Statue of Liberty, and... he lets the arm drop, adjusts his baseball cap and says: "OK guys, that's enough. Let's not fuck with perfection."
I should add at this point that I'm the only person in the audience, having been given special dispensation to sit in on Diamond's afternoon sound-check. In a few hours the place will be filled with 10,000 swaying, singing and, in some cases, gently weeping fans, each jumping to their feet at the end of every song in honour of their septuagenarian idol. But for the time being, it's just me, Diamond and his band, and I can't help but be a little thrilled by this. I am well aware that there are people who would trade vital organs to be in my shoes.
The man once known as "the Jewish Elvis" incites a very fierce type of idolatry, perhaps because those who adore him are so frequently obliged to defend him. Critics have for years been extremely sniffy about Diamond. Even if they concede that songs such as "Sweet Caroline", "Cherry Cherry" and "Solitary Man" are really rather good, they will point to the tight trousers, the abundant chest hair and, most emphatically, the shirts – the sequin and rhinestone-encrusted monstrosities that he wore in the 1970s and 1980s – and say that he is self-aggrandising and hokey, that he is the very opposite of cool.
Diamond claims to be immune to the concept of what's fashionable, though it can't have escaped him that over the past few years his stock seems to have risen. This is, in part, down to the success of his 2005 album 12 Songs, on which the producer Rick Rubin stripped away the soapy orchestration and put the emphasis back on the voice. Then there was 2008's Glastonbury, where he was a huge hit among the muddy masses, and proved that, whether or not the songs are to your taste, he is one hell of a showman. Finally, in March this year, in a mark of acceptance from the critical elite, Diamond was finally inducted into the Rock'n'Roll Hall of Fame.
"Being back in vogue? It's fine," he says, a little flatly, back at his hotel. "It's always nice to be accepted by your peers. But it has not, and cannot, affect what I do. It's not as if I have any say in it. The public accept you, then they forget about you, and if you're lucky they accept you again. It's how this business works."
Curiously, Diamond talks just as he sings. His rich, tremulous voice would sound wracked with melancholy reading the football results. But, up close, he looks nothing like the person he becomes when performing. Wearing a black sweatshirt and specs, with wiry grey hair poking out from under a baseball hat, he seems shrunken and frail. If you saw him on the street, you'd be hard-pressed to recognise him as the man striking triumphant Statue of Liberty poses on stage. Apparently this suits him just fine.
"I'm a very low-profile person and I don't really relish the concept of stardom," he states. "It does not help me as a creative person. I want to be a human being. As a writer I want to be able to pick up on the vibes of what's happening in the world, and I can't do it from behind a castle wall."
But whether he likes it or not, Diamond is a star, not to say the focus of immense curiosity to his fans. He has a hard time getting to grips with this, and certainly doesn't find the prospect of interviews thrilling. Though he is never less than polite, it takes him a while to meet my eye. More disconcerting is the squidgy pink worry ball that he brings with him. When he picks it up, it's as if he's raising a flag that reads: "For the love of God, don't ask me that!"
I wonder what on earth keeps him going. Many other 70-year-olds with his wealth and status would have retired to the golf course by now, but the Diamond show just keeps on rolling. He has sold around 125 million records and was the most profitable live act of the 1990s. Right now he is in the midst of one of his biggest tours in years. He has already been to Australia, New Zealand and South Africa, and is now doing a six-week stretch across Europe, culminating in 15 concerts in the UK. Why do it?
"Because I'm never happier than I am when I'm on stage. Sure, life on the road can be hard going, but there's always a friendly face around somewhere, there's always a poker game to be had, or someone to take a walk with out of my hotel. I'm very comfortable with what I do. I've been doing it a long time."
Last month Diamond also released The Bang Years, an album of his songs covering the brief period between 1966 and 1968, when he was making the move from being a writer-for-hire on Tin Pan Alley to a performer in his own right. The sheer concentration of hits, from "I'm a Believer" and "Red Red Wine" made famous by the Monkees and UB40 respectively, to "Girl, You'll Be a Woman, Soon" and "Monday, Monday", is astonishing when you consider the brief period over which they were written. Diamond may have rarely been the critics' choice, but these songs are as embedded in our cultural consciousness as anything by Bob Dylan.
Prior to his time with Bang Records, Diamond says he was "essentially a failure. It had been hard, really hard. For eight years I was living hand-to-mouth and I wasn't at all confident that it would work out. I was knocking on doors and writing songs, but most got nowhere. I had half-a-dozen recordings made of my songs, but none of them really by any known groups, and none of them made the charts. I was playing pretty much any place that would hire me – ski lodges, bowling alleys, high-school gyms."
Diamond was also studying medicine at New York University, though he struggled to focus on his work. "If you're going to study pre-med, it's very time-consuming and I didn't have the time or inclination. I was writing songs in all my classes, I was writing songs on the subway trains coming into school. In between times I was bringing songs to Tin Pan Alley and knocking on doors – I'd jump on a train and 10 minutes later I would be in the music district. Eventually something had to give, and it wasn't the music."
Diamond was, he says, a quiet child. Raised in Brooklyn, he worked on Saturdays in his father's clothes shop, quietly memorising the songs he heard on the radio. His parents adored music too, and would crash weddings just so they could go dancing. But even they were a bit concerned about their son's desire to abandon a career in medicine in order to write pop songs.
"At that time rock'n'roll didn't have the cachet that it does now," reflects Diamond. "A career in music was looked down on, and the whole milieu of rock'n'roll was kind of a circus at the beginning. It didn't gain any respect until people like Bob Dylan and the Beatles got involved and raised the bar."
It is a surprise to find that he never meant to become a singer. His plan was to earn a living behind the scenes as a songwriter, though early cash-flow problems meant he had to sing and play instruments on the demos he made, and he found his voice suited the songs.
Even so, he didn't take to performing at the start. Early television footage shows him gaping at the audience as if trying to stare down a would-be attacker. "Yeah, I struggled," he says. "You get on stage and you don't know what to do with yourself. One of the most important elements of performing is that you have to know who you are and what you represent. I thought to myself: 'Am I Frank Sinatra? Am I Harry Belafonte? Am I Elvis?' Those were the choices I thought I had. After trying all of those people I realised I was going to have to settle for being me, on stage and in my songs, and that realisation was an epiphany. I mean, for a while it was a problem, as I didn't think very much of myself. But I found that if I could be true to myself, and reflect my own situation, that it would strike a chord with millions of people out there who were confronted with the same problems."
For Diamond, these problems included lengthy periods of separation from his wife Jayne Posner and their daughters Marjorie and Elyn, culminating in divorce in 1969. Diamond had been on a professional roll after "I'm a Believer" was a hit with the Monkees. More singles followed, this time sung by Diamond, including "Cherry Cherry" and "Solitary Man", but being away from his children was, he says, awful. "I had been writing, recording and performing non-stop for five years. For my kids, dad was always out of town. I'd said so many goodbyes to them that it took a toll. I carried that pain with me on the road. As many toys as you bring back, it doesn't replace the time that you've lost."
Diamond vowed that he wouldn't make the same mistakes with his next marriage. In late 1969, he wed Marcia Murphy, a TV production assistant, and the following year their son Jesse was born. "I decided that this time I would be a proper family man. I did not want to put my second family in the same situation that I put my first in." Thus, Diamond quit touring and stayed at home with his children (he and Murphy had another son, Micah) until they started school. Was domestic life a comedown after the glory of being a successful musician?
"Not at all. I loved every minute of it. We were all together as much as we could be, and I travelled east to see my daughters on a continual basis. It was a magical time. Even when they were all at school and I was back on the road, I would check the touring schedule to make sure I was always home on the kids' birthdays. I was trying to put things right."
When he returned to touring, Diamond started seeing a therapist. "I saw it as a way to learn about myself. I considered it a luxury – it was a time that was just devoted to myself, and it was for my own good. As difficult as it was, I think it has made me a better and more understanding person. I still do it now. It's like maintenance for my mind."
Diamond's career went from strength to strength in the 1970s. Somewhat improbably, he was asked to audition for the role of Travis Bickle in Taxi Driver, though he declined due to singing commitments, but still Hollywood beckoned and in 1980 he was offered the lead role in the film The Jazz Singer, opposite Laurence Olivier. The film was a disappointment at the box office, but the soundtrack was a smash.
Having watched their children grow up, Murphy and Diamond divorced in the mid-1990s in what is reputed to be among the most amicable and generous settlements. But Diamond is still saddened by the fact that the marriage fell apart. "It is," he says cautiously, "very difficult for a woman when her husband is adored by the world. Although I tried to compensate for it by making my wives feel like the centrepiece of my life, they knew instinctively that it was the music that came first and they couldn't compete. My dedication to my work has never wavered and, really, I don't see that chemistry changing. I need to be with a woman who understands my work ethic and is secure enough not to be threatened by it. I don't take the adoration seriously. It's one of the things that I have to deal with, but it doesn't keep my feet warm at night. You have to get off stage, and when you do, you're as mortal as anyone."
Since a long-term relationship with Rae Farley, an Australian 30 years his junior, ended three years ago, Diamond has been single. Is he OK with that? "Well, I read a lot now," he says, looking rather maudlin. "I always have my guitar wherever I am, and I always have a music player in my hotel room. So I don't find that I'm a lonely person any more. I guess I've adapted to it." When he's away, he talks to his children and grandchildren (there are seven) on Skype. "The world has got a lot smaller through technology," he says. "That's a real blessing for someone like me."
When he's not on tour, Diamond's home is in Los Angeles; he also has houses in Colorado and New York. He may have become accustomed to his own company but it is clear he is nowadays infinitely more comfortable standing on stage in front of thousands. "I have more fun there than I have just about anywhere else," he tells me and he does, it's true, make it look like fun. Later that evening, when he emerges from beneath the stage in a black suit (he's ditched the sequins, thankfully), he looks 10ft taller and 20 years younger. The crowd, predictably, go nuts and it's impossible not to get swept up in the euphoria. I even feel a little lump in my throat when he starts talking about his grandmother. "When I'm up there I like sweeping all the elements and the unimportant distractions away from my life and saying, 'This is what I am,'" Diamond says. "It's the best feeling in the world."
'Neil Diamond: The Bang Years 1966-68' is out now on Sony. Diamond begins his UK tour on Tuesday at the LG Arena in Birmingham. For more information on dates and venues, visit neildiamond.com