Daniel Barenboim: Superman who carries the baton for Wagner

He's taken the work of Hitler's favourite composer to Israel and doesn't care if his forays into world affairs cause outrage

A week ago today, Daniel Barenboim raised his baton to begin Wagner's Flying Dutchman. By next Saturday evening, he will have spent 41 hours, spread across two weeks, conducting his Deutsche Staatsoper Berlin company in every one of the German composer's 10 major stage works. So intense is the challenge set by Wagner's operas that many conductors go through their career without performing one. No one has ever before attempted Barenboim's task of conducting all of them in immediate succession.

In most conductor's hands, the idea would be dismissed as a gimmick. A few years ago, Barenboim's contemporary, Lorin Maazel, conducted the nine Beethoven symphonies in one day at London's Festival Hall. As an athletic challenge it had some merit. As a musical event it was worthless. But such is Barenboim's stature, and his personal integrity, that one knows that the only purpose to his venture is musical.

Barenboim's Judaism and Israeli citizenship are at the core of his personality and have prompted many of the ventures that have taken him beyond the musical world and into a form of politics. So it is all the more remarkable that it is Wagner, above all other composers, with whom he is now associated. The German composer, who died in 1883, was, of course, Hitler's favourite; his music sometimes accompanied Jews as they were sent to the gas chambers. But the current Wagnerthon in Berlin is merely Barenboim's latest attempt to rehabilitate Wagner, especially in the eyes of his fellow Jews. As he puts it: "Wagner was not responsible for Auschwitz".

Barenboim is now the main conductor at Bayreuth, the annual festival in deepest Bavaria devoted to Wagner's operas. Last July, conducting his Staatskapelle Berlin orchestra at a concert in Tel Aviv, he prompted calls from Israeli politicians of all main parties that he be banned from future public performance in Israel when he conducted the Prelude to Tristan und Isolde as an unprogrammed encore. Not a note of Wagner's music had ever before been played in concert in Israel.

The Tel Aviv Wagner performance was typical Barenboim. It is not enough for him to transport his audiences through the power of his musicianship. Like other musicians before him, such as Yehudi Menuhin, Albert Schweitzer and Jan Paderewski, Barenboim uses his talent on a far wider stage, a concern which surely stems from the remarkably varied life he has led.

His first incarnation was as a child prodigy pianist. Barenboim was born in November 1942 in Buenos Aires to parents of Russian descent. He gave his first official concert when he was seven years old. The Barenboims moved to Israel in 1952, and Israel has been the constant thread running through his life ever since. He flew back there to play for the troops at the start of the Six Day War in 1967. He did the same thing in 1973 during the Yom Kippur War. And one of the enduring images of the Gulf War is of Barenboim and the Israel Philharmonic Orchestra giving concerts in gas masks as the Scud missiles rained down.

But although he was, and remains, a passionate Zionist, he has also pioneered his own dialogue with the Arabs. In February 1999, he became the first Israeli to perform in Palestinian territory when he gave a piano recital at the Palestinian Birzeit University on the West Bank. "It was mind-boggling and terrifying. I got very frightened ... I thought, 'What am I doing here?' I knew that anything could happen." Three weeks ago he was banned by the Israeli authorities from giving another such concert in Ramallah; Israelis have not been allowed to travel into Palestinian areas since the second intifada.

In August of the same year he organised an unprecedented summer school in Vienna. Israelis and Arabs from a number of countries aged between 14 and 25 came together for three weeks to play in one orchestra. Barenboim used his own mixed heritage to explain his aim to the orchestra: he lived for the first 10 years of his life in Argentina, the next nine in Israel, 15 years in London and 15 years in Paris. Now he flits between Chicago and Berlin.

His extracurricular activities mean that he is far from universally popular. Many point to his overweening ego and self-belief and his refusal to acknowledge any alternative points of view. The Wagner performance in Tel Aviv, for instance, was genuinely upsetting to many in a nation founded in the wake of the Holocaust. But because Barenboim was convinced that the ban on Wagner is misguided, he simply ploughed on regardless.

Unlike most prodigies, whose flame extinguishes once they reach maturity, Barenboim made the transition to genuine musician with ease, with a reputation for searing, fresh interpretations of the cornerstones of the classical repertory. By the 1960s, he was established as the leading light in a group of musicians, including the violinists Itzhak Perlman and Pinchas Zukerman, and the cellist Jacqueline du Pré, who were transforming musical life with their energy. Barenboim's marriage to du Pré was one of the iconic relationships of the Sixties. They were treated more like pop stars than classical musicians. An entire industry has grown up around the relationship, most recently the film Hilary and Jackie, which was widely regarded by those who knew du Pré – and Barenboim – as a travesty. Although Barenboim refuses to discuss the relationship, and especially his rumoured affairs during her incapacity from multiple sclerosis, he was deeply shaken by the film's unrelenting portrait of a sexually ravenous du Pré and his own callous behaviour towards her. Du Pré died in 1987, 15 years after being diagnosed with MS, and Barenboim is now married to the pianist Elena Bashkirova, with two teenage sons.

When Barenboim first took up the baton there were some other pianists who occasionally conducted, but it was generally frowned upon. You either did one thing or the other. Barenboim simply ignored such views and, from the mid-Sixties, struck up a close relationship conducting the English Chamber Orchestra. In 1975 he took up his first music directorship, with the Paris Orchestra, which he led for 14 years. He dominates the musical scene in Berlin now as he once did in Paris. But in 1988, having barely moved in to his office as director of the new Bastille Opera, he was sacked after accusations of greed following the revelation of his conducting fees. Today he is reputed to earn more than £1.5m a year from his two conducting positions, in Berlin and as music director of the Chicago Symphony Orchestra, which he became in 1991.

When he took over the Deutsche Staatsoper in 1992, it had not lived up to its traditions for decades. He has turned it into one of the most renowned opera houses in the world. His life has been one long, restless whirlwind of activity, the musical inseparable from the rest. Another great musical lifeforce, the Russian cellist Mstislav Rostropovich, celebrated his 75th birthday last week. Rostropovich is so much the Grand Old Man of classical music that it is difficult to think that only 15 years separate them. Barenboim remains as youthful in spirit, and as keen to provoke and to challenge as ever, as he ends his sixth decade.