Daniel Barenboim: How the maestro made classical music the hottest ticket in town

With the news that Daniel Barenboim is visiting London to play Beethoven, a few words come to mind: "tickets"; "gold dust"; "living legend". Pianist, conductor and possibly today's most articulate verbal communicator about matters affecting musical perception, Barenboim is surrounded by an aura that feels almost mythic. When he performed the complete cycle of Beethoven's 32 piano sonatas at the Royal Festival Hall two years ago the excitement the series generated was second to none. Now he's back, presenting four concerts with the Berlin Staatskapelle, the programmes built around the five Beethoven piano concertos, which he directs from the keyboard.

The association between Barenboim and Beethoven goes all the way back to the 1960s when the pianist, still in his mid-twenties, recorded the complete Beethoven sonatas on EMI Classics – a recording that has rarely, if ever, been bettered. His recording of the concertos from 1968, with the New Philharmonia Orchestra conducted by Otto Klemperer, is likewise a classic. Barenboim and Beethoven have, over time, become almost branded together.

And with good reason. Concluding his Beethoven Sonatas cycle at the RFH, Barenboim played the final work, the Sonata in C minor Op 111. The journey he wrought evoked not just a piano keyboard, but an entire orchestra. No wonder the chance to hear him play all the Beethoven piano concertos is the hottest musical event in London.

He is the "chief conductor for life" of the Berlin Staatsoper and its orchestra, the Staatskapelle. But perhaps he is even more celebrated for co-founding the West-Eastern Divan Orchestra (Wedo) with the late Edward Said, placing young Israeli and Arab musicians side by side to share the endeavour of music-making; the orchestra often seems like a rare beacon of light in a complex and worsening situation where such dialogue is usually impossible. This outlook only strengthens the branding of Barenboim with Beethoven, whose Ninth Symphony included the "Ode to Joy" – "All men shall be brothers" – and whose opera, Fidelio, concerning the rescuing of a political prisoner, the Wedo and Barenboim brought to the Proms last year.

Some, of course, would argue that Barenboim's legendary status is somehow manufactured, and that the mystique about him has built via extra-musical factors, not least the Wedo itself. But, to Barenboim, music is life, the processes of the one intimately related to those of the other.

His life has been an extraordinary one; now 67, he has rarely been out of the spotlight since his days as a child prodigy – though he has argued that there is no such thing as a child prodigy. Time and again a new phase has added another layer to the legend, often by pure coincidence – or fate, if you prefer. Either way, the cumulative effect has grown to signify more than the sum of its parts. Musician, writer, legend, life: everything is connected. That, incidentally, is the title of his latest book.

Barenboim – his name means "pear tree" in Yiddish – was born in Argentina; his Jewish immigrant grandparents had met on the boat from Russia. Both his parents were piano teachers, so the sound of the instrument was with him from the beginning. "I never met anyone who didn't play the piano until I was old enough to go out in the street," he recalls, "because whenever the doorbell rang it was somebody coming for a piano lesson. In my childish brain everyone played the piano!" His mother gave him his first lessons, after which his father, Enrique, took over. "My father from very early on taught me that you could not just play without character," he says. "He had a horror of anything mechanical or routine about making music. I'm very grateful to him, because in that I've never changed."

He gave his first concert at the age of only seven, in Buenos Aires. When he was ten, the family moved to Israel. Two years later, a visit to Igor Markevich's conducting masterclass in Salzburg brought him to the attention of the great conductor Wilhelm Furtwängler, who declared him a phenomenon. Unlike some others, Barenboim has always been a conductor as well as a pianist, with each art informed and strengthened by his understanding of the other.

International debuts and stardom followed apace, but it was a chance encounter in London on New Year's Eve 1966 that built the next part of the Barenboim legend. At a friend's chamber music evening, he met a young British cellist named Jacqueline du Pré. They were soon inseparable, and when the Six Day War of 1967 broke out, they flew to Israel and were married at the Wailing Wall in Jerusalem as a gesture of solidarity.

But even this episode might not have entered the public's consciousness so strongly without the fortuitously-present camera of film-maker Christopher Nupen, a friend of the young couple and their circle – which included the violinists Itzhak Perlman and Pinchas Zukerman. Nupen's intimate, informal documentaries endeared them all to a wide new audience via TV, notably through the Portrait and Trout films.

Jacqueline du Pré was diagnosed with multiple sclerosis at 28 and died after a terrible, protracted illness on the night of the great storm of 1987. Since then Barenboim has never returned to certain works that were associated with her; and the atmosphere of the Trout film and its magical collaboration has never been recaptured. Although he has made occasional chamber music recordings and given concerts with younger colleagues, including musicians from the Wedo, he says that "it was the circumstances of the people – with Jackie, Zukerman and Perlman – that drove that chamber music. I haven't found new partners since the 1970s."

Not so in his personal life: he quietly started a relationship in Paris with the pianist Elena Bashkirova during the course of du Pré's illness. They later married and have two sons: the younger, Michael, is now a violinist and one of the leaders of the Wedo.

What had originally taken Barenboim to Paris was the post of music director at the Orchestre de Paris, where he remained from 1975 to 1989. The Paris stint went wrong spectacularly, though, when in 1989 he was fired from the directorship of the Opéra Bastille after a fierce falling-out with Pierre Berge, the organisation's government-appointed president. It was not to be the only time that Barenboim would find himself at the centre of a very public appointment controversy.

Ten years later, the vacant directorship of the great Berlin Philharmonic became a "two-horse" race between Simon Rattle and Barenboim, who had been resident at the Staatsoper and Staatskapelle in the same city since 1992. The players elected Rattle and around the world rumours flew of Barenboim's fury. Later, in 2006, he left the music directorship of the Chicago Symphony Orchestra, apparently tired of the extra-musical wheeling and dealing that American orchestras demand of their chief conductors.

Lorin Maazel nominated him his successor at the New York Philharmonic four years ago, but Barenboim turned down the job, quoted as remarking: "Nothing could be further from my thoughts at the moment than the possibility of returning to the United States for a permanent position."

But the Staatsoper has become his home. Maybe there's a certain poetic resonance in seeing him – a stocky, somewhat pugnacious-looking figure with waistcoat and cigar – in his office in the historic opera house on Unter den Linden, previously in the heart of East Berlin and a stone's throw from the Reichstag. Had he lived in this city in the 1930s he would have faced death; today he is one of its most powerful individuals.

In his Reith Lectures of 2006, "In the Beginning was Sound", Barenboim described the orchestral sound that he grew up hearing from the Israel Philharmonic. In the 1950s its members were mostly refugees from Nazi Europe, musicians who had trained in the traditions of Furtwängler, Bruno Walter and their generation of conductors. When Barenboim encountered the Berlin Staatskapelle for the first time, he found it "chilling", he says, to realise that he was hearing exactly the same sound: it had of course originated in pre-Second World War Germany. In his work with the orchestra, Barenboim has been striving to maintain its distinctive individual nature in an era when the sounds of most orchestras have become all but indistinguishable from one another.

It was with the Berlin Staatskapelle, too, that Barenboim attempted to shatter the biggest musical taboo in Israel. An unofficial ban stems from the fact that some of Wagner's music was played while the Nazis' victims were being taken to the gas chambers. Barenboim argued that, while nobody should be forced to hear music with such terrible associations, those who did not share those associations should not be prevented from hearing great music that was not responsible for its own misappropriation. Forced to drop one act of Die Walküre from his programme for the Jerusalem Festival of 2001, he presented the Prelude and "Liebestod" from Tristan und Isolde as an encore instead. He made an explanatory speech beforehand inviting those who did not wish to hear it to leave the theatre. Reputedly about 50 protestors walked out, with some 1,000 remaining; the encore went ahead. But a ferocious and often shocking discussion followed, with some incensed Israelis calling Barenboim a "fascist" – all of it captured by film-maker Paul Smaczny and much of it included in his documentary on Barenboim, Multiple Identities.

The title of Smaczny's film was well chosen: the paradoxes around Barenboim continue. He became the only Israeli citizen to hold a Palestinian passport. He's more articulate on international affairs in the Middle East than most politicians, yet has no intention of venturing into politics himself. But, crucially, he has the ability to think beyond the mundane, to take a longer, wider view and express this in an idealistic way that captures the public imagination, even if it also provokes outrage among his detractors. Introducing his Reith Lectures, he explained that he was attempting "to draw parallels between the inexpressible content of music and the inexpressible content of life" and that "the impossible attracts me more than the difficult".

Perhaps he has been attempting the impossible in his work with the Wedo – yet together he and the young orchestra attract thousands of listeners hungry for the passion of their playing and for the hope that they represent. It, too, is the result of a coincidence and/or fate: he and Said met for the first time by chance in a hotel lobby. He has declared that the orchestra is not politically motivated but founded on the ideal of common humanity: knowledge of the "other" has to be the first step towards a dialogue. Leaving each ignorant of one another and separated – including physically – is no solution. He recalls that Edward Said once declared: "My friend Daniel Barenboim and I have chosen this course for humanistic rather than political reasons, on the assumption that ignorance is not a strategy for sustainable survival."

"It's not easy to be optimistic about the future of the Israelis and the Palestinians," he told me, "because I think both sides will have to change completely their way of thinking about the other. And the solution can only come through each side's acceptance of the right of the other to have another narrative – therefore to accept the suffering of the other, to accept that historical part of it and then arrive at the acceptance of certain elements of today's reality.

"The destinies of these two peoples are bound, whether they like it or not, because they both want to live in the same place. I think the Palestinians will have to accept the right of Israel to exist, while Israelis have to accept that many mistakes were committed, not always willingly, but because of the Jewish people's need to find a home. Only when that part has been psychologically worked at by each side can there really be hope. It involves a very unusual mixture of understanding the past, seeing the present and out of those two building a common future. And I have to stress common future, because I think there are Israelis who dream that they will wake up in the morning and the Palestinians will have disappeared. And many Palestinians dream that the Israelis will disappear. Neither is going to happen. Therefore to create a future, you have to create a common future." He has written that he has not felt comfortable in Israel since the 1960s: "After the Black September of 1970, the then prime minister Golda Meir said: 'What is this talk of the Palestinians? We are the Palestinian people!' At that point it clicked in my mind: this was morally unacceptable."

In his recent book Everything Is Connected, he demonstrates the way that music is a metaphor for life and for society. To take one example, he expounds on the difference between power and strength – the first a matter of force, the latter a question of fortitude – by showing that the same applies to the playing of a single chord on the piano. Too much force, and the chord has no sustainable strength because the inner notes will not be audible. And the inner voices must be heard, whether in a piece of Beethoven, or in a society that wants to be strong and sustainable.

Music, he asserts, is indivisible from life; we can improve each through understanding the other. "What is, ultimately, perhaps the most difficult lesson for the human being – learning to live with discipline yet with passion, with freedom yet with order – is evident in any single phrase of music," he writes. His philosophies, influenced by figures ranging from Spinoza to the late Edward Said, are elemental and dig into the deepest, essential forces at work in life and art. And this leads us back to Beethoven. There is a mysticism in Beethoven, especially his late works, in which suggestions of the cyclic nature of existence, the renewal of the soul and the redemption of the human spirit can be sensed shining through even the most abstract forms. Few musicians convey this as powerfully as Barenboim, who manages to tell us more than most about life, our society and our souls.

But there's nothing elitist about Barenboim: his whole point is that music is for everyone, is part of everyone and is inextricably woven into the fabric of existence. His presence as a powerful musician who also has the moral authority to speak difficult truths is profoundly inspiring. No wonder that we flock to hear him. As he says: "In front of a Beethoven symphony we are all equal."

Daniel Barenboim and the Berlin Staatskapelle, Royal Festival Hall, London SE1 (0844 875 0073) tonight and 31 January, 1 and 2 February. Tickets are sold out but the concerts will be live-streamed free into the venue's Clore Ballroom.