Quietly and unfussily the Cheshire-born pianist Stephen Hough has conquered the music world. Russian virtuosi come and go in a whirl of hammered octaves. American whiz-kids dazzle briefly then fizzle away. From the Far East an endless parade of mercurial youths flit like butterflies over the ivories without ever ruffling the soul. Hough’s progress, by contrast, has been so stealthy that when Gramophone magazine and readers of The Times recently anointed his mesmerising Hyperion recording of the five Saint-Saëns piano concertos as the best classical CDs of the past 30 years (beating Karajan, Rattle, et al), the reaction in some musical households must have been “Stephen Hoo?”

Yet his rise continues, with a unique accolade by the Proms. In the coming season the 47-year-old will play all four Tchaikovsky piano concertos — starting on the First Night with No 3. So the obvious first question is: why does almost everybody know No 1, and almost nobody know the other three? Is there a rational reason?

“There are reasons,” Hough replies, “but I don’t think that they are rational or particularly intelligent. The First is such a great piece that it works even in less good performances. The Second, by contrast, needs to be played not only more often but better. It must be held together architecturally, otherwise it can seem repetitive and overlong. But I love it. Although very different from the First, it’s every bit as good.”

But hasn’t Hough doctored it a bit? “Yes, I do make one significant change in the slow movement,” he says. “Right from the first performance people felt that it didn’t have enough piano in it. Tchaikovsky’s own letters suggest that he wasn’t happy. It’s as if the soloist leaves the room, the host absent from his own party. And it does feel weird to perform. You play your pants off in the first movement, then just let everyone else take over. So at one point I have rescored the solo violin and cello parts for the piano.”

Doesn’t Hough worry about getting into trouble with Tchaikovsky scholars for tampering with the great man’s notes? “Well, one of the chief scholars heard me playing my version in America and he didn’t notice that we’d changed anything, although he said that we managed the slow movement well!”

What about the Third and Fourth Concertos? Do they deserve resuscitation? “The Fourth, which is really the Concert Fantasia, is unjustly neglected,” Hough says. “It’s a very attractive, balletic piece. The Third wasn’t finished, and had a curious history — it started life as a sketch for what Tchaikovsky thought would be his Sixth Symphony, until he wrote the Pathétique. So he decided to turn the original piece into a piano concerto. But he never finished it, so we have this single movement. Unless you really love Tchaikovsky, you wouldn’t necessarily choose to play it.”

Curiously, Hough never studied the Tchaikovsky concertos, not even the ubiquitous No 1, while he was a student (at Chetham’s School and the Royal Northern College in Manchester, then at the Juilliard School in New York). “Everyone else learnt No 1, and I didn’t want to enter into that competitive thing you get at music colleges,” he says, revealingly. “But about four years ago I was teaching a student who was working on No 1, and I felt the music starting to unfold like a flower. I decided to learn it there and then.”

And does the elusive personality of Tchaikovsky also “unfold like a flower” through these piano concertos? In recent years there’s been a furious debate about the nature of Tchaikovsky’s life and, particularly, his death. Where does Hough stand on the theory that Tchaikovsky deliberately drank untreated water during a cholera outbreak to take his own life?

“There’s no conclusive evidence either way, but I’m convinced that he didn’t commit suicide,” Hough says. “When they told Tchaikovksy that he had cholera he was shocked, which isn’t the response of someone who had decided to kill himself. And there’s another issue. He was slightly snobbish and cholera was seen very much as a working-class death — something you got if your hygiene wasn’t

up to scratch. Psychologically, too, suicide doesn’t feel right. Tchaikovsky was in a good mood. He was happy with the reception for the Pathétique. He realised he had written a masterpiece and was accepting new commissions.”

Why, then, was the suicide myth (if it is a myth) perpetrated? Hough has his own rather wild (or rather, Wilde) conspiracy theory. “Tchaikovsky died at around the time of the Oscar Wilde trials, and there was such anti-homosexual hysteria surrounding them. I just wonder if the suicide rumour gained credence because people didn’t want to admit that this homosexual genius was a normal happy person like anyone else. And of course in the 20th century the suicide theory also suited the Soviet view of homosexuality.”

Would rejection of the suicide theory change our view of Tchaikovsky’s music and the man himself? “Certainly of the man,” Hough says. “If you think of him as a self-loathing neurotic you get the wrong picture. He was very passionate, and of course depressed at times. Which Russian isn’t? But he always pulled out of these moods.”

Homosexuality features large in Hough’s thinking right now. He has already written eloquently — in newspapers and on his blog — about being both gay and Roman Catholic (twice in his life, he says, he came close to entering the priesthood). [Writing on the subject in the Catholic newspaper The Tablet, Hough commented that St Paul’s prohibitions against homosexuality have to be considered in the context of their time. “As with slavery,” he added, “the Churches will have to re-evaluate their teaching on the issue.”

Now he is bringing the two strands together by writing a book about gay theology. “I think the title of it will be It is Not Good for the Man to be Alone,” he says. Meaning what? “Well, it’s taken from the Creation story in Genesis: the observation that everything God sees in the Universe is good, and the first thing that isn’t good is this isolated human being without a partner. I want to tie that into the idea that if homosexuality is in nature, which we now know it is, then God must think it’s good.”

It won’t be Hough’s first religious book. Two years ago this remarkable polymath (he also composes, writing music he describes as “tonal with a twist”) brought out The Bible as Prayer, a compendium of what he calls “highlights” from the Old and New Testaments. Coming from a fiercely Protestant family (his great-grandfather was head of the Orange Lodge in Liverpool) his conversion to Catholicism at 16 must have been a huge wrench. “Yes, I suppose that in part it was my teenage rebellion,” he says. “The equivalent, for me, of taking drugs. It happened while I was attending the Dartington Summer School in Devon. I stumbled across morning Mass at Buckfast Abbey and was entranced by it, not just because it was a beautiful ceremony but because it reached beyond the everyday. And I found it intellectually convincing .”

How does his faith help him as a man and a musician? “It has given me a perspective,” Hough replies. “I won a big piano prize when I was 21, the Naumburg Competition, and was completely unprepared for the life and pressures that followed. I had a difficult few years and realised that I had to develop better physical, mental and spiritual health if I was to survive. I had to adopt the attitude that, within the big picture of the Universe, this next concert really doesn’t matter hugely — though of course one wants to play one’s best.”

And how does that relate specifically to Christianity? “Well, St Francis said that the Crucifixion involves the three things we most fear — suffering, disgrace and death. So if they cease to worry you, there’s no reason not to be happy for the rest of your life. I now believe that there isn’t any suffering or failure — in one’s career or personal life — that really matters in the end. Having said that, I’m conscious that I haven’t yet suffered much. Let’s see if I can stand by my beliefs when the real thing comes along.”

Stephen Hough plays at the First Night of the Proms next Friday in the Albert Hall, SW7 (020-7589 8212), and then on July 28, Aug 8 and 28

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