What is certain is that he's the world's busiest maestro, and he made history this season when he conducted opening night at the Metropolitan Opera and then, two days later, opening night at Carnegie Hall. No one had ever done that duo before.
But his home is in St. Petersburg, Russia, and that's where correspondent Bob Simon caught up with him in his natural habitat, the podium.
Gergiev has got to be the world's most unkempt, unshaven and unlikely of conductors.
But don't let that put you off. When Gergiev is conducting, he is in another world. His eyes roll inwards. His hands perform a ballet for 10 fingers. He coaxes the musicians; he cajoles. He's a sorcerer, casting a spell.
"If you love the music, the musicians will feel it. If you love the music, it's like infectious," says Gergiev. "The musicians around you are reminded that they also love music very much. And then, and they, everything goes away … It just disappears, because you are talking to another world. And that's the magic of art."
Gergiev casts his unworldly spell in one of the world's most magnificent music halls: St. Petersburg's Mariinksy Theatre. It was built 160 years ago and it was the music room of the Czars. The Soviets renamed it the Kirov. And Igor Stravinsky called it the most sacred of temples.
Gergiev has been worshipping, and worshipped here, for 25 years. And he joins others famous composers, including Tchaikovsky, Wagner, Rachmaninov, Mahler and Verdi, who have stood at that same podium.
But Gergiev doesn't just make music. He's also a manager, an entrepreneur, a fundraiser and sometimes, it seems, the mayor of St. Petersburg.
Unlike most opera houses such as the Met and La Scala, the Marinksy produces both opera and ballet. And Gergiev is both the artistic director and the general manager of everything. At New York's Lincoln Center, four people do those jobs.
Gergiev's road to the Mariinksy was a strange one, because this most Russian of musicians isn't really Russian at all.
Gergiev grew up in a remote region of the Caucases, part of the Soviet Union, but a lot closer to Afghanistan than St. Petersburg. His father was an officer in the Red Army.
His mother, he says, dragged him off to piano lessons when he was 8: "I wanted to be anything, but not musician. Not musician."
But his parents persisted, and made him take an entrance exam for the music academy. When the results came out, the teachers broke the news to them gently: "Unfortunately, they told my mother, 'He absolutely doesn't feel anything about music. You have to think maybe normal school, but music school's not for him.'"
But he ended up in music school after a while and was discovered. It was decided he would be a conductor. At the age of 19, he was sent to the great music academy of St. Petersburg, then Leningrad. And it was every young musician's dream.
Before long, he became the darling of the West -- one of the Soviet superstars like Nureyev, Baryshnikov, Makarova. The difference is they defected, but Gergiev always came home.
Did it ever occur to him to defect?
"I didn't think this way. It is not that musician becomes much better when he's in America, and he's not interesting at all when he's in Moscow. This is not true," says Gergiev, who compares it to the brilliance of a diamond.
"This brilliancy. You know? And if you hold it in Siberia, it will give you the same brilliance, as it will shine in New York. It's the same, but I never saw a person who was boring. Boring. Then he moves somewhere and everyone says, 'He is a genius artist.' Anywhere. I never saw it in my life."
But how did Gergiev become what he calls a "genius artist?"
Gergiev says there was one day, one moment, when he changed from a soccer-loving 14 year old to a devotee of music. It was the day his father died, and he sat down at the piano.
"Was the worst day of my life so far. And it was difficult, but I was somehow rescued. I know in sitting and playing the same chords, it was some maybe melancholy sadness," says Gergiev.
His father died at the age of 49. And Gergiev's friends, like the American soprano Renée Fleming, say they believe that's what's made him run so fast -- a premonition that he,too, would die young.
"He said this to me early on that he didn't think he'd be doing this for a very long time," recalls Fleming. "I'll never forget that, and I thought 'You're a young man, what a strange things to say.' But he's had sort of this inner drive and this inner, almost, to an obsessive point of having to just do as much music every day, every single day, as he can."
And that's precisely how Gergiev saved the Mariinksy Theatre after the Soviet Union collapsed and the funding stopped. He never stopped. Many maestros have a breakneck schedule, but Gergiev takes his orchestra, his chorus, his dancers, everyone, with him. And they're always in demand.
How does the maestro make it to concerts on time? Well, he doesn't. Gergiev is famous for ending rehearsals about the time a performance is supposed to start, while patrons stroll the foyers and musicians roll the dice.
"I think our system is more flexible," says Gergiev.
It has to be. That's how things are in Russia. Many nights, the orchestra, the chorus, and the audience wait for the performance to begin for close to an hour. Meanwhile, the maestro chose to take 60 Minutes on a backstage tour.
"Maestro, I think your concert is about to begin," says Simon.
"If we go there, it will maybe start," says Gergiev.
It did. And all was forgiven.
"He's a force of nature," says Fleming. "I love watching him in action and kind of seeing the sounds and particularly the sounds he creates with his own orchestra and his own chorus. Completely unique."
After the concerts, there's the carousing, old comrades, and vintage vodka every night. When does he sleep? We could never figure that out.
But what's tolerated at the Mariinksy does not go down at the Met. And the maestro's been made aware of that. Gergiev was on time and stone cold sober when he walked from his New York hotel to the Met to preside over opening night - the most coveted and prestigious date on America's musical and social calendar. The opera was "La Traviata," starring his biggest fan, Renee Fleming.
Gergiev's association with the Met goes back 12 years. General Manager Joseph Volpe wanted him on board so badly that he created a job for him as Principal Guest Conductor. The Met had never had one of those before.
"At the Met, he's on time. We understand each other," says Volpe.
But Simon asked him about a misunderstanding that once happened when Gergiev showed up late for an opera called "Parsifal."
"There was not a misunderstanding. This is not a misunderstanding. If he's late, he's wrong. There was no confusion in this case," says Volpe. "I went down and I said, 'Valery, this cannot be. You don't wish to do this to me.' And he didn't say anything. But he's been on time ever since."
Gergiev turned 50 last year and there was an enormous celebration. Everyone knew the subtext. His father had never seen 50. He could now relax.
But did he? Of course not. Just ask his mother about what she thinks of the life her son is leading today.
"Very unhappy about the way, the life, he leads," she says. "Doesn't have time for rest or no time for sleep, nothing."
Does he think that he works too hard?
"Yeah. I can't argue with my friends because they're right. I also think that today I have to think about my children, my family, my wife," says Gergiev.
"For conductor, 50 is not bad. I mean, it's not autumn. It is not late evening. It's kind of lunchtime, you know?"