From the Royal College of Music to the Paris Conservatoire to a job at the Paris Opera to principal flute with the Berlin Philharmonic was a 15-year slog: from then on, fame and money have accrued like ivy round an oak. To his grateful record company (RCA), he's The Man With The Golden Flute: his natural habitat is top of the charts.
There's even something oak-like about his presence: an intransigent little Ulsterman who bears the marks of having lived hard, and whose mid-anecdote pauses are those of an after-dinner speaker: whisper who dares. Everything about him proclaims that this is a man you don't push around.
And the facts bear this out. He won't, for example, play in France: he claims he won't even fly over the place if he can avoid it. "I don't want to play for people who permit what the French secret service did to the Greenpeace protesters in New Zealand" (ie murdered them). He donates his broadcasting profits to an Aids education charity: "We've got to show the kids that, if they don't watch out, this thing will have their name on it."
Tomorrow he will play his first big London recital for five years: the main reason for his long absence lies in the tactics of the management he recently sacked. "They're like so many managements now: they want to put one of their conductors with one of their orchestras with one of their soloists, and take a huge cut on the transport. I wanted some of that money - and I didn't want to play with their conductor and orchestra. I thought their whole attitude was insolent." And he's sick and tired of doing outdoor summer concerts in Kenwood - "or any other wood".
"Musically speaking, they're nothing events. Who wants to engage with the spiritual content of Mahler, in front of 10,000 peanut-eating folk who aren't listening? They wanted me to do that kind of thing because they thought I'd attract the crowd, but that's not why I play music."
On the other hand, he's not exactly averse to attracting the crowd, nor to hitting it big in the record shops. Three months ago he and his pianist friend Phil Coulter launched an album called Legends, which has been near the top of the charts ever since. "But we just can't knock Riverdance and Lord of the Dance out of first and second place, because Michael Flatley's on TV somewhere, every single day."
Galway and Coulter have had a long history of larking about on stage - including the stage of the White House - over their religious divide (Derry-Catholic Coulter versus Belfast-Prod Galway). "And I said we really should make a record, because there's an awful lot of Irish music we know, and now's the time - the Celtic background is becoming the world foreground. Time to cash in on this Celtic revival."
So he's happy with this crossover thing? "It's about making money. The Three Tenors? That's not a career move! That young girl who plays the violin in a wet T-shirt, that's not a career move either. It just means some guy behind her is ripping her off like you can't imagine. And he's telling her that later on she will be wonderful. But she will not! Because she's swimming in the middle of all this mess. But..." - a canny smile - "if you do make money, people will give you permission to do other things as well. When I told my record company that I wanted to record the Boulez sonatina, they didn't throw me out of the window of the 14th floor. They just said, `When?'"
James Galway is now 58, living with his collection of gold flutes and his flautist wife in a village near Lucerne where they regularly give small concerts for christenings, masses, communions. He's become a diet freak - "People are less worried by what they eat," he observes, "than what they put in their cars" - and ruefully regrets the drinking he did in his youth. And he still describes himself as an amateur at heart: "Why else would I go to the annual flute convention in America?" Good question: 3,000 flautists in one room sounds like an unusual kind of hell.
But, then, there's one good reason, says Galway, why so many people should want to play the flute. "Because it's not hard to play. Anybody can play it. It's just hard to play real good. The oboe and bassoon are much harder, and a lot more expensive. The basics of flute-playing will do for most people, most of the time. On the other hand, how many flute players can just walk out like Horowitz and electrify the crowd? Very few." No false modesty here.
And when the cuddly mask slips, he's notably unsentimental about technical shortcomings. He likens players who are not note-perfect to actors playing Hamlet who get the words wrong in "To be or not to be".
"You get guys like that in competitions, and they should be kicked out immediately. For some reason, people like all the tears and snot and stuff. Personally I can't stand it."
He makes an exception for David Helfgott, however: "That's a guy who's had real difficulties, and it's marvellous he can do what he can do."
What is his advice to young hopefuls? "Examine your talent, and get your IQ tested. Ask yourself if you're dreaming. And don't imagine it's going to be easy, even if you are good. You have to expect things like this" - holding up a callused finger. "I still practise three or four hours a day."
Is there anyone good coming up? "A young Swiss player called Emmanuel Pahud. He's got the potential to be one of the greatest."
I catch Emmanuel Pahud after a concert with the quartet he leads at the Louvre, where he has been amply demonstrauing the qualities that so impressed Galway: an impeccable technique; a warm, powerful sound; an attack that is rare in an instrument normally pigeonholed as "pretty". And if we're talking apostolic successions, Pahud's career fits neatly: he is now what Galway once was, principal flute with the Berlin Phil. Though Pahud's path, unlike Galway's, was smooth from the start.
The son of an itinerant telephone engineer, Pahud caught the flute bug from an older boy living next door in Rome. Four-year-old Emmanuel heard him play Mozart's flute concerto: "I told my parents that I wanted to play the same instrument, and the same piece." It was 11 more years before he did play that piece (and a full 24 before he got round to recording it for his EMI debut disc, just out), but the tuition he received in the meantime, from a series of good teachers, meant that his talent had an unusually secure base. "Each teacher insisted on a different kind of embouchure. That variety is very useful to me today."
And what drew him to the flute? "It's the only wind instrument which you blow on top of, rather than into: it's therefore the closest to the human voice. Obviously I couldn't analyse that when I was five, but now I see the truth of it. The challenge is to extend its possibilities, and to give more density to its sound. I don't just want to evoke the sound of birds...
"I think in terms of different places to put the air, to get different kinds of voice. Sometimes I feel I am blowing the sound out here" - indicating the back of his head - "or here" - his ears - "or here" - his nose. "Of course that's just an impression, but the sound reflects real differences. You need to know what is physically happening. You need to know which cavities you use for which particular sounds." This may all seem fanciful, but it makes good sense.
And, like Galway, Pahud is what producers call "media-friendly". He's relaxed and articulate, comfortable in front of television cameras, and quite happy to discuss marketing techniques, while insisting that his crossover work should not be "harmful to the classical image". He sees world music as the key, and wants to put together a disc drawing on African, Indian, Japanese, and South American flute traditions. "But I shall imitate their sound on my flute, the instrument I know how to play. I have to stick with what I know."
With the endearing ineptitude of those whose English is a few words short of a thesaurus, Pahud speaks reverentially of the great "dinosaurs" who dominate the story of the 20th-century flute: the French Jean-Pierre Rampal, the Swiss Aurele Nicolet, and Galway himself. Is this 28-year-old virtuoso the next dinosaur-in-waiting?
James Galway in recital with Phillip Moll: 7.30pm tomorrow, Barbican, London EC2 (0171-638 8891)
Emmanuel Pahud: Mozart Flute Concertos, Berlin Phil/ Claudio Abbado, on EMI CDC 5 56365 2