Baton charge: Valery Gergiev on being the world’s most prolific maestro

It's official: Valery Gergiev is the busiest conductor on Earth. Last month, statistics from the classical-music website Bachtrack confirmed this to a public that wasn't particularly surprised: Gergiev has long been notorious for a schedule that might slaughter a less resilient soul. One concertgoer commented that the site's proffered number for Gergiev's performances last year, 88, was incomplete; the true figure was probably closer to 130. That averages one every 2.8 days. No wonder orchestras are said to wonder whether he will materialise in time for rehearsals, or even for concerts.

In Amsterdam, the morning after performing Shostakovich's Symphony No 15 at the Concertgebouw with his beloved Mariinsky Orchestra, Gergiev does materialise on time, looking somewhat worn. Those powerful eyes are showing their sizeable whites, and the dusky voice is 20 per cent tone to 80 per cent gravel. Directing the Russian composer's devastating last symphony, the maestro, 57, has once again pushed himself to the limit.

How does he feel about being the planet's busiest conductor? "Accused of being?" Gergiev half-jokes (he isn't one for excessive laughter). Then he adds more quietly: "Or recognised as? Let's put it more dangerously. I can be accused of doing too much: correct. But I cannot be accused of doing too much with too many orchestras. I focus on the main relationships in my life."

That means the Mariinsky – he has been the St Petersburg opera house's general director since 1996 – and the London Symphony Orchestra (LSO). Occasionally he appears at the Met in New York, or in Milan, Vienna, Berlin or Sweden; he also convenes his World Orchestra for Peace twice a year. "I value relationships more than 'prestige conducting'," he says. "Anyway, there is no such thing for me now as 'prestige conducting' because I did all that 20 years ago. There was no orchestra left which I had not conducted several times at least – but it is not what makes me happy."

When Gergiev was appointed principal conductor of the LSO in 2004 (he took up the post three years later), doom-mongers predicted disaster. Gergiev, surely, was too busy; the LSO, flagship orchestra of the UK, would play second fiddle to the Mariinsky. "Those people were totally wrong," Gergiev declares. "Five years ago people were talking about why I and the LSO shouldn't work together: 'He's so busy, he cannot find time for LSO...'" He breaks into a rare, impish grin. "Sorry! Wrong! The LSO is a big, big part of my life."

What, then, has happened to the LSO in the Gergiev years? "I think we make music," he says simply, "and we work intensively, with 50, sometimes up to 64 concerts each year. We create an atmosphere which makes nearly every concert in some way special and in many ways interesting. One story is our work in London; the other is our appearances in cities around the world, which I remember with a very strong sense of satisfaction." Touring has extended beyond Western Europe, America and the Far East to new locations in the Baltics and Balkans, from Tallinn to Zagreb. "The LSO is a fantastic ambassador for British musical culture," Gergiev says.

"Other orchestras also do it, no question, but I think we offered programmes which were able to make a strong statement: an entire cycle of Prokofiev symphonies in many places, lots of Shostakovich and a big variety of Stravinsky."

Russian repertoire is high amongst Gergiev's priorities; so, too, are living composers, notably Henri Dutilleux and Rodion Shchedrin, who have both been spotlit in extended LSO series. But his Wagner and Strauss have loomed large in recent years, his Mahler symphonies recorded in concert and released on the LSO Live CD label are approaching a complete cycle, and he happily champions his preferred singers in Italian opera. Sometimes his approach to non-Russian repertoire attracts controversy; more often he sparks full houses and standing ovations. His excess of energy seems to draw out mystic, magnetic forces wherever he, and they, may be.

Gergiev was born in 1953 in Moscow to parents of North Ossetian origin; his father was a military officer and was subsequently posted to Vladikavkaz, where the family was raised. Valery and his sister Larissa, who is now head of the Mariinsky Academy of Young Singers, were gifted in music from the start; but the death of their father when Valery was 14 perhaps spurred him into the intense determination that has marked his whole career. Ossetia still inspires his loyalty: he arrived quickly to give a concert there after the tragedy of the Beslan school massacre, and dived in with musical moral support for the populace when Georgia and Russia clashed over the region in 2008.

His studies progressed in St Petersburg (then Leningrad) under Ilya Musin, and things began modestly, with a second prize in the Herbert von Karajan Conducting Competition when he was 23 and an appointment at the Armenian Symphony Orchestra in the early 1980s. Soon he began to work at the Mariinsky Theatre (which was still the Kirov) as assistant conductor to Yuri Temirkanov. It was an extraordinary vote of confidence from the orchestral musicians there that launched Gergiev on the path he has followed ever since: they elected him principal conductor in 1988, despite competition from such established figures as Mariss Jansons and Gennadi Rozhdestvensky.

But today Gergiev can seem as much muscular statesman as musician. He has immense ambitions for the Mariinsky; and, facing head-on the inextricable, inevitable ties between the arts, politics and big money, his tenacity and diplomatic skill have borne substantial fruit. It is largely thanks to his efforts that a new Mariinsky concert-hall was opened in St Petersburg in 2006, and that a sizeable new opera house is being constructed there.

"Mariinsky 2" is an extremely big deal. Much postponed and with a cost to the state said to run to some 18bn roubles (£400m), nearly double the initial estimate, it is reputedly one of the most expensive theatre-constructions in history. Part of the original design by Dominique Perrault, featuring a golden dome, was ditched three years ago; a new contract was then awarded to the Canadian architects Jack Diamond and Donald Schmitt, working with the Russian firm of KB ViPS Architects. It was to have been finished by June this year, but is way behind schedule.

"The expectation now is that it will be open for the White Nights Festival next year," Gergiev says. "It is a huge, difficult project, but let's hope it will also be a successful part of this long story. It started in 2003 when there was a feeling in my country that the economy was improving and St Petersburg, being a great cultural centre, would gain a lot if there was one more opera house built. It's clear that the Mariinsky became a global presence a long time ago."

Inevitably this brings up the subject of the Russian president and former prime minister, Vladimir Putin. "People all over the world say repeatedly that he is a close friend of mine," Gergiev remarks, neither confirming nor denying it, but adding that the rumour that he and Putin are godfathers to one another's children is "totally untrue".

"I have known Mr Putin for a long time and I was very hopeful that when he became prime minister we would not lose completely the integrity of Russia," he says. "People forget that in 1999 the question was whether Russia would survive at all. Mr Putin had a historical role simply to save the country from collapse. That's quite a big task. History will judge, and of course history judges already.

"After the collapse of the Soviet Union there was no state support for the arts, or very little, and no private sponsorship. Today there is state support and also sponsorship; though maybe for the Mariinsky it's a little easier than for some orchestras in more remote regions." This could be rather an understatement.

"Mr Putin," he continues, "never ignored the importance of cultural institutions. For him organisations such as the Hermitage, the Bolshoi, the Mariinsky and the Pushkin Museum were always a priority – not No 1, but also not No 100. And this is where I find it appropriate to say he was a good leader for Russia.

"There is no way in my country for the president or the prime minister to totally ignore the Hermitage or the Mariinsky, and that is why we meet several times a year. There is no way, I believe, for Mr Putin personally to forget that you have only one Hermitage in the world and it belongs to Russia; you have only one Mariinsky and it belongs to Russia. How can you ignore it? People would say he is arrogant or stupid, so he cannot do that, and that is my understanding. And that's how the story of the new theatre started."

The 2,000-seat venue is an addition to, not a replacement for, the historic Mariinsky. It will build on the huge demand for performances during the annual White Nights Festival and beyond; above all, Gergiev emphasises, it will enable the company to expand its work with schools and young people.

"Our programmes for schools and universities are already huge," he says, "and they will be even bigger. The ambition is to work not only with all universities and high schools, but also with primary schools for children from five to ten years old: this, for me, is the golden heart of our public, the children who are waiting to see their first Nutcracker or their first Swan Lake.

"This process will be supported by our power to give so many performances that will be sold out. The success of our commercial activity will mean that we can afford to do what we want to do."

Gergiev's ambitions to widen access in St Petersburg may be steaming ahead – but what about Britain? With serious cutbacks threatened to UK arts organisations and education, would he be willing, as principal conductor of the LSO, to fight for the arts here as well?

"Not only if I am asked," he says at once. "I am always ready to do it – and whatever possible will be done at the right moment. When a new government comes in, it takes up to a year to understand what the promise is, or was; then what the reality is; and the big economic reality outside. Nobody can grant any country or city in the world a leadership for five years unless there is a very dynamic process of thinking, not only about economic developments, but also cultural developments; if these become nationally important then they become also globally important. I believe that the LSO, the Royal Opera House and the British Museum are national symbols.

"If you go to Japan and visit a Japanese restaurant, you respect the customs: you take off your shoes. If you don't respect the traditional cultural rules, you are seen as an unwanted visitor. In the same way we have to respect our own national identities, then respect the national identities of others: then the world will become a better place. It's easy to speak about those issues," he adds, "but it's very difficult to see how in many parts of the world this will become the norm."

In other words, state funding for the arts should be part of a government's respect for its country's traditions. "Support for cultural institutions should not become smaller and smaller – it's dangerous," Gergiev declares. "It's not going to be the American way in the UK." He points out that the tradition for private philanthropic support for the arts in the US has been in place for more than 100 years.

"Many great institutions there have been supported for decades; sometimes more than 50 per cent of their strength comes from individuals' or corporate support – which now is also changing. It would be very dangerous and naive to think this will happen overnight in the UK, to think that the state support for certain arts institutions can reduce because the individuals' contribution will increase. I am afraid both will reduce. And that would be deadly."

Gergiev's most immediate challenge in the UK, though, is a musical one: Mahler's Ninth Symphony, the last one completed by its composer, the centenary of whose death falls this year. It's a work so personal that it seems almost to belong to a world beyond our own. "When you conduct some composers' final symphonies – Tchaikovsky's Sixth, Bruckner's Ninth, Shostakovich's 15th and certainly Mahler's Ninth – then you feel some extra mystical energies around you," Gergiev affirms. "This is not energy that brutally imposes itself; it's something you cannot touch and you cannot describe, but it's there. Every performance of Mahler's Ninth Symphony is destined to at least start with an extra element of mysticism.

"The last page certainly is a huge effort, like closing but also like opening: it moves to the unknown. There's a fear, a solemnity, about this quiet. The music is not in the notes you hear, but in between them; you have in a way this horrifying silence, yet it's at the same time something sacred, a dying or departing spirit. Therefore another sonority should be produced, and the silence is as if you practically stop breathing. There is some mystical feeling there, and maybe it has to be left to this unknown force."

Many intangible forces seem to surround Gergiev: he is a musical tiger who burns extremely bright. The energy he conveys in performance is unmistakable; his style is unique, with quivering fingers, burning focus in the eyes and astounding physical magnetism. Everything is on the edge. How does he survive his own intensity?

"My strategy is to build relationships," he replies, "and to work with certain orchestras and singers long-term. My work with singers like Natalie Dessay, René Pape, Anna Netrebko, Olga Borodina and many more – this is something to build and build and build." With the French soprano Natalie Dessay he recorded Donizetti's Lucia di Lammermoor: "I simply asked her what would be her most important wish." And the Mariinsky's recording of Wagner's Parsifal is, he says, the result of 15 years' rewarding work with the German bass René Pape (it is on the Mariinsky's CD label, a sister label to LSO Live).

"My recipe for survival is this: unless you stop enjoying it, do it and make sure you are able to be inspired and maybe also inspire some people around you," he declares. "If you feel this is not the case, stop."

Gergiev has streamlined parts of his schedule – he says he now travels to the US three times a year, rather than seven or eight, and wants to see more of his children, Abisal, Tamara and Valery junior. His wife, Natalya Debisova, is a pianist from Ossetia; they married in Vladikavkaz in 1999 when she was 19.

Still, with a year ahead in which he will assume a new mantle as president of the International Tchaikovsky Competition, direct a star-studded White Nights Festival, and initiate a lavish LSO season full of glittering Russian delights, there's no sign that the Gergiev phenomenon will abate. He thinks big, aims high and gets results. We may yet be very glad that he is here.

Gergiev conducts the LSO in Mahler's Symphony No 9 at Barbican, London EC2 (020 7638 8891) 2 & 3 March