Daniel Barenboim: The musician never ducks a challenge

This week, Daniel Barenboim played Beethoven in Ramallah and let it be known that he had accepted honorary Palestinian citizenship, thus setting the seal on his campaign to persuade Israel's oppressed Palestinians that they haven't been forgotten by the West. "I hope that my new status will be an example of Israeli-Palestinian coexistence," he said as he accepted his new passport.

Now reaching the pensionable age of 65, this evergreen musician is in many ways at a turning point in his life, which has run a remarkably consistent course.

Look at the photograph of Barenboim playing Mozart's spinet in Salzburg at the age of 10. It could almost be him at the keyboard now: the same power-packed physique, the same serenely intent expression as he studies the same tiny hands – for him, it's a matter of lifelong regret that he can't produce the stretch to play Bartok's second piano concerto, which is one of his favourite works.

And, in every sense, he's now looking forward rather than back. He's about to publish a philosophical book on music and time, and he's embarking on a new relationship with La Scala, in addition to his tours and his leadership of the Berlin Staatskapelle. And he's marking this pivotal moment with a series of performances that bring his pianistic career full circle.

As a depressed 17-year-old in Israel, coming to terms with the fact that as an ex-child prodigy he was no longer of interest, he seized on an invitation to play at an obscure Tel Aviv auditorium called Journalists' House. "With the recklessness of adolescence I said yes, I would like to play all the Beethoven sonatas," he recalls.

The result was both perfect therapy for his depression, and the start of a lifelong relationship with what he regards as the most complete creative diary ever kept by a composer. Later this month, he'll repeat this stunt in eight concerts at the Royal Festival Hall, and he'll conduct a linked series of seminars on art and society entitled Artist as Leader.

But back to Ramallah. As time goes on, his hopes that a solution can be found to the Arab-Israeli deadlock are dwindling. "Behind the political problem is the human problem," he says. "On one side the lack of security for Israel, and on the other the terrible living conditions for the Palestinians, who voted for Hamas out of sheer desperation. The longer the real illness is not dealt with – rather than just the political symptoms – the more ingrained it will become. Unless something is done very quickly about this, there will be the one-state solution which the Arabs always wanted – with an Arab majority. And that would mean the end of the Jewish state, which would be looked back on as one very short episode in the history of the Jews. I don't want to see this, but it's within the realms of possibility."

Are his oft-repeated warnings not listened to in America? He shrugs. What about Israel's response to the Reith Lecture he gave there two years ago, in which he broached these matters? Another shrug.

But he's not giving up the fight. The West-Eastern Divan Orchestra, which he set up with his late friend Edward Said, the Palestinian-Arab historian, is going from strength to strength. Barenboim has a neat explanation of why a symphony orchestra should be the perfect template for democracy: "When you play in an orchestra you have to express yourself, and simultaneously listen to what others are playing and saying." Under this scheme, at each desk an Arab is placed next to an Israeli; in the first half of their concerts, an Arab violinist is leader, with an Israeli violinist taking over after the interval.

Their Ramallah concert in 2005, after rehearsals under heavy military guard, represented a bold gesture on behalf of young people in the region, and after it Barenboim made a speech including these words: "Either we all kill each other, or we share what there is to share."

But he resists the facile label of an orchestra-for-peace – "this is an orchestra against ignorance" – and he's continuing to break down that ignorance in a variety of ways. Last year, his foundation opened a conservatoire in Nazareth for Palestinians living in Israel, and it regularly sends music teachers into the occupied territories; he recently donated a €50,000 prize he'd won to finance a research project on Arab music in the villages, much as Bartok and Kodaly once did in Transylvania.

Meanwhile, there are Israelis who still haven't forgiven him for breaking their unwritten taboo by performing Wagner in Israel. He defended his decision by insisting that, in refusing to perform the composer's works out of deference to the sensitivities of Holocaust survivors, Israel's musical establishment was handing the Nazis a posthumous victory. "Not playing Wagner has harmed the Israel Philharmonic artistically," he argued at the time. "I don't see how you can really understand Mahler and Schoenberg if you don't know your Wagner."

He's keen to bring Beethoven into this argument by saying that, along with Bach, Debussy and Boulez, he was one of that tiny handful of composers whose music summed up everything that had happened before, and showed the path to the future. And in Beethoven, he suggests, we have an exemplar in other ways too. "His virtuosity was not like Paganini's or Liszt's – for virtuosity's sake – it was for the complete experience he wanted to communicate, the experience of being human. Of being deep, humorous, thoughtful, of being able to do things which other mortals are not able to do."

People have for centuries identified Beethoven's music with the idea of struggle, he adds. "But I don't want to cheapen that by saying he was struggling against his deafness, or the autocratic nature of Napoleon – that's totally unimportant. But there is reflected in his music the human being's struggle to better himself. VC The struggle to change, to simplify. If you look at his sketchbooks you see how he struggled to simplify his ideas, which usually came to him in a form which was too complex for his own taste and judgement. All his work moves from being complicated to being simple, to being more concise." Barenboim says his own interpretations of the sonatas are continually evolving: comparing his EMI recordings from the Sixties with his Deutsche Grammophon ones from the Eighties, and both with his 2005 videos for EMI, I would describe that evolution as moving towards an almost visionary authority.

And that is what he has always aimed for. "To separate the technical from the expressive side in music is like separating the body from the soul," he once wrote. He never had any teacher apart from his father Enrique, and Bach was the principal deity in Enrique's pantheon. In his childhood, Daniel played most of the preludes, fugues and partitas: this was the basis for his mastery of polyphony, and for what he calls the pianist's necessary sleight of hand.

"The piano is a neutral instrument, which cannot seduce by virtue of its sound alone. But it is possible to create with it the illusion of sustained sound similar to that of a string instrument." And he has never practised mechanically: "My father's teaching was based on the belief that there are enough scales in Mozart's concertos." Barenboim's winning way with Mozart today is a vindication of that belief.

He gave his first concert in Buenos Aires at seven: he may have been fonder of football than practising, but he was precociously gifted. In 1952, when he was 10, his family moved to Israel – the tango disc he affectionately recorded later in life testified to his Argentinian nostalgia – and in that same year he gave his first concerts in Vienna and Rome. He made his first recordings in 1954. He studied composition with Nadia Boulanger in Paris, and joined Igor Markevitch's conducting classes in Salzburg, where the teaching assistant was Wolfgang Sawallisch.

But the conductor who loomed largest in his firmament was Wilhelm Furtwängler, who was so impressed by his playing that he penned a letter hailing him as "a phenomenon" and invited him to play with him and the Berlin Philharmonic. Enrique declined the invitation on Daniel's behalf – he deemed it too soon after the atrocities of the war for a Jewish family to visit Germany – but the letter served Barenboim as a calling-card for years to come.

Furtwängler died soon after this encounter, but Barenboim went on devotedly absorbing his musical wisdom through recordings, by studying his annotated scores, and by talking to people who had worked with him. Attending Carlo Zecchi's conducting class in Siena two years later, he commenced friendships with his fellow students Claudio Abbado and Zubin Mehta, the latter becoming a lifelong soul-mate. He gave his first London concert in 1956, and his first in New York the following year. And in London he also met Clifford Curzon, whose Mozart playing has deeply influenced his own.

London in the Sixties was the recording centre of the world, and here Barenboim forged many enduring musical relationships, both with orchestras – notably the English Chamber Orchestra – and with musicians including Pinchas Zukerman, Itzhak Perlman and the cellist Jacqueline du Pré, who in 1967 became his wife, and with whom he made some notable chamber recordings, including a much-loved video of Beethoven's "Ghost" Trio. "Until illness began to cripple her," Barenboim writes of du Pré in his autobiography A Life in Music, "she was able to do whatever she wanted on the cello, and needed very little practice. She had a capacity to imagine sound such as I never met in any other musician. She really was a child of nature – a musician of nature with an unerring instinct."

This relationship was the spur that drove Barenboim's restless spirit to conquer an ever-widening variety of musical worlds. In 1969, he made his first foray into the humbler art of accompaniment, with a recital with Dietrich Fischer-Dieskau. And in 1972 he conducted his first opera, Mozart's Don Giovanni. That was in Edinburgh, but it was in 1978, at Berlin's Deutsche Oper, that he first conducted the opera composer who has since become his specialism – Wagner.

He intensified his relationships with both Wagner and Germany throughout the Eighties and Nineties, basing his chief musical fiefdoms at the Bayreuth Festival – where he conducted regularly for 18 years, including annual Ring cycles between 1988 and 1992 – and the Berlin Staatsoper, of which he became general music director in 1992, and where he famously conducted two complete cycles of all 10 of the composer's major operas in just over a month in 2002.

Meanwhile, in 1987 he had become artistic director of the Bastille Opera in Paris, where his friendship with Pierre Boulez stood him in good stead, even if it couldn't prevent his later falling-out with the political establishment. He subsequently went on to become music director of the Chicago Symphony Orchestra. Barenboim has likened the Staatskapelle orchestra, when he first encountered it at the Staatsoper, to "the most wonderful antique furniture, its beauty covered by layers and layers of dust". Taking that dust off, he quickly turned it into the world-beating ensemble it is today.

And these days his musical radicalism is intensifying in tandem with his political zeal. He no longer wastes his breath in the lost battle against Mozart-as-muzak: he's more interested in excoriating both the professionalisation of music, and the period-performance brigade, who in his view have completely lost the plot.

"In Europe, even the listeners are professionalised, with music regarded as an ivory tower. Fewer people had access to it in the 19th century, but those who did connected it instinctively with the condition of being human, and with all the other arts. Now you get people who know every note of Schumann but haven't read a word of Heine, and literary people who have read every word of Heine and know nothing of Schumann. Music has been taken out of its place in the totality of culture."

Hence his delight at the way Western classical music is catching on in Venezuela and China. The pianist Lang Lang is one of his prize pupils. In 2006, at Kofi Annan's instigation, he conducted what was probably the first major concert of Western classical music in Ghana, delivering Beethoven's Ninth with a big orchestra to an audience of thousands. "And they knew it was something important – that it had to do with humanity, not with a profession.

"Somebody asked me the other day what sort of legacy I wanted to leave," he says suddenly. "How did I want the world to remember me? I had to say I don't think like that, I don't really care. I don't spend time thinking about the future of my records. But it gives me a tremendous amount of pleasure to think I can go to London and play at the Festival Hall, and people will come and listen. I say that unashamedly."

Another key photograph from his early life – marrying du Pré in Jerusalem, with full Orthodox panoply – prompts a different question: how religious is he? He laughs. "Not at all. I feel Jewish, and I feel at home with the Jewish heritage, but the Jews I look up to from the past are people like Spinoza and Einstein – people who were not religious. I am not religious either – I don't even believe in myself." Nor in an afterlife? "No!"

Daniel Barenboim's Beethoven series begins at the Southbank Centre, London SE1 on 28 January ( 0871 663 2500; www.southbankcentre.co.uk)