Now, still on the admissible side of thirty, Metheny is already ahead of what many musicians would be obliged to regard as the peak of a career, and still rising. His records sell 100,000 a throw. He has scored several films, the latest being John Schlesinger's spy thriller The Falcon and the Snowman which took Metheny's collaboration with David Bowie into the pop charts. Along with Miles Davis, Wynton Marsalis and, to a lesser extent, Weather Report, his band is that rarity - a jazz-based outfit of improvisers that can guarantee itself a gig somewhere in the world most nights of the year.
Nothing about Pat Metheny in person - who is one of the most amiable, unaffected and broad-minded individuals ever to put his bank manager's mind at rest about the decision to be an artist - suggests that success has much changed him or corrupted his musical ear. He still bears the same old rag-mat haircut, battered sneakers, boyish grin and drawling Jack Nicholson intonation that he undoubtedly had kicking his heels on the Kansas City sidewalks as a teenager.
He continues to play a wide variety of music, much of it in the company of the Jarrett-like pianist Lyle Mays, and characterised by conventional song structures, imaginative use of electronic technology, ethereal deployment of voices, a strong sensation of mid-West open spaces and the capacity to be either background music or serious listening. This last is a surefire guarantee of popular success and a surefire guarantee, moreover, of a chorus of complaints from purists about abandoning the One True Path of jazz.
One indisputable fact confounds much of that aggravation and that is the immense respect in which Metheny's work is held by exactly the kind of jazz players that the hard-core fans would most admire. Metheny's current partnership with Billy Higgins and Charlie Haden, which produced the ECM album Rejoicing - a blistering confection of Ornette Coleman tunes, bebop and semi- quavers flying like ping-pong balls - has continued to flourish. There is every prospect of a European tour with that ensemble, an event to gladden the hearts of all guardians of the faith.
Metheny was in England in March, on a pre-tour publicity run for a two-month string of European gigs with his regular band, which ends in Britain this month. We had met two years previously, and I had asked him all the customary questions about his musical origins at that encounter. He had been a rock fan in the hippie era when, to him, hippies were grown-ups.
"I saw Hard Day's Night fifteen times when I was twelve," Metheny had said then. "'She Loves You' came out when I was nine or ten, and it was like all those moments in your childhood when you suddenly notice something you've never noticed before. It was the first time I really got chills after hearing music."
Latching on to pop music so young had the curious effect of making Metheny's teenage rebelliousness, when it came, expend itself on the pop orthodoxy he had already absorbed.
"When I got to fourteen or so," was his explanation, "I went the opposite way, rebelling against rock & roll completely. I didn't want anything that wasn't Miles or Coltrane or Sonny Rollins."
It made Metheny "a very sophisticated fourteen-year-old". When other kids of his age were needling cops or hot-rodding cars, Metheny - having learned to play jazz guitar with indecent haste and voracious enthusiasm - was starting to play professionally with jazz stars visiting Kansas and mixing with musicians more than twice, and sometimes three times, his age in the elliptical, downbeat, corner-of-the-mouth intuitiveness of the jazz life.
His big break came when he persuaded Gary Burton to let him sit in. Metheny immediately joined Burton's band and his brand of lilting, lissome single-line improvising, jaunty country-music chords and apparently effortless swing (the latter strongly reminiscent of the late Wes Montgomery) soon made him a guitar celebrity. He was immediately absorbed by the idea of producing music of his own, though, a music that owed as much to pop and country music as jazz and which, in its early stages, closely resembled a more muscular, technologically inclined and less fastidious version of Burton's own work. It took the roots of Burton's popularity - melodiousness, rock & roll time, catchy tunes, sophisticated improvisation - and magnified them. Yet, for all the fact that Metheny has committed himself to a middle road, he speaks as obsessively - as a man of his relaxed demeanor can - of the crucial significance of doing things his way.
"I refuse to be intimidated by success," Metheny says. "And I don't think I've even for a second played down to people. The musician has to be playing at his peak for the music to really sound right. You have to feel that the person is playing the best they can play, and what they really want to play. When I listen to my early records, I might want to take a lot of it back now but at the time we played it, that was it. In some parts of the hard-core jazz community they will say things like the only reason Charlie Haden would play with me is because he's a nice guy. A record company president, on the other hand, might say 'Sell half a million records or we don't want to know about you'. I'm not interested in either position because they're political/economic points of view - they're both wrong, and they have nothing to do with music."
Metheny's work with Billy Higgins and Charlie Haden has proceeded in parallel with the activities of his own band and has developed from being a casual try-out to a working ensemble which has now toured extensively in the States. There is now enough live material on tape to make a new trio record that, in Metheny's words, will be "serious business". It is the counter to all the carping about Metheny that he is a jazz-inflected MOR player who produces music to calm your nerves in the dentist's.
The trio represents a genuinely musical partnership between three front-rank improvisers all of whom have a deep and wide understanding of the post-bop innovations of Ornette Coleman.
Interestingly, Metheny is a rare example of a player absorbed in Coleman's work who none the less is completely hooked on conventional harmony. Like Coleman, he loves music that swings. Like Coleman, he is a highly rhythmic improviser. But Metheny's fondness for pop music means that he likes songs, too, which leads him to admire the saxophonist's early compositions, the melodies of which positively dance. But Metheny believes that bassist Charlie Haden had more of an impact on Coleman's early progress than is generally acknowledged.
"I've learned from Charlie a whole bunch of Ornette's tunes that have never been recorded, some of his hippest ones, and we may even do a quartet record with Ornette who's been to hear the band several times and likes it. Ornette's harmonic thing is unbelievably advanced but the unsung hero of it is Charlie. He has an incredible ability to make up harmony as he's going along. My mother could sit there and bang random notes on the piano and he could play a bass part that would make it sound as if she was thinking a line. It imparts an inner logic that you don't get when Ornette plays with other bassists.
"Interestingly, Rejoicing has sold almost as many in the States as the group record First Circle, that's over 100,000. We get kids coming to the trio gigs who only know the band stuff and they still dig it.
"I don't buy the theory that there's got to be a heavy backbeat on everything for them to follow it. That said, I'm well aware that there are some things going on for me that definitely help - one being that I play the guitar at a time when the guitar is the instrument, another is that what I play is extremely melodic and develops a tradition that goes back to Lester Young of telling a little story when you play and, of course, we tour relentlessly which is an incredible promotional aid."
Metheny's favourite guitar players, and the strongest influences on his own approach, are Jim Hall and Wes Montgomery - even though Montgomery died when Metheny was still in short pants. He admires improvisers who, as he puts it, "think like drummers". It is, he says, "the most attractive thing about Wynton Marsalis, that rhythmic feel. He'll play some phrases on top, some behind, he can put it in a lot of different places - most guys have only one way they can phrase and they'll phrase it that way no matter what, fast or slow.
"I loved all that Jimmy Smith organ stuff when I was a kid and the way Wes would play with him. It makes you think of a rhythm for the phrase first and the notes later. Jim Hall has that, Wes had it, Bill Evans had it, Miles has it, and Keith Jarrett is very rhythmically sophisticated, too, I think, though I would question some things about his attitude and I wish he wouldn't sing when he plays. But the players that have that quality have it no matter what else they do, and it doesn't leave them.
"People put down Herbie Hancock a lot these days but, if you went into a room with him and just a piano, he'd blow your mind. George Benson, too - he could go out and make two jazz records a year, if he wanted, and be on top of the polls for ever ...".
Sometimes you wonder whether the real reason why Pat Metheny is such an unapologetic defender of the virtues of traditional western harmonic practices is that he just simply loves work, gets restless when he isn't playing, and finds the challenge of trying to develop new ways of playing old songs more interesting than some more metaphysical pursuit of musical "freedom". Bebop - after all, the most sophisticated form of harmonic playing jazz has ever developed - is the one that requires the greatest discipline in the player. But discipline, as Metheny himself says, to make something new of it.
"It's hard to make it sound real. It's not too hard to figure out what notes go on what chords but average bebop players sound pretty boring today, even though bop is popular again. But it's hard to make it sound interesting to people who aren't already interested in the idea that they're hearing bebop."
But considering what an admirer of that mode of construction he still is, even though the idiom he adopts with his own group doesn't resemble it, doesn't the new technology of electronics obscure exactly those bop guitar virtues that he cut his teeth on?
"Well, a guitar is still a guitar. But it can now be a triggering device for a lot of other things. A synthesiser isn't a keyboard, remember. It's a system of electronics that can be triggered by many instruments. And they're going to improve dramatically over the next ten years, some of them are already incredible. The most intriguing combination musically would be to have everything at once. Good improvisers, good technology, a group spirit, all integrated."
And are there many examples of that kind of integration in the musical world around him?
"I have to say that of all the New York jazz heroes at the moment, very few of them work for me with the exception of Wynton and his brother. I don't have a feeling with many of the others that they have the basic grammar of improvising under control. Ornette's got something that enables him to bypass the Charlie Parker tradition but he's the only one who could really do it. Coltrane, even in the later stages, was always relating to some kind of harmony. Those records of the great Miles quintet in the Sixties - it sounds like they're playing free but the structure is there. That's what it's supposed to sound like. My big qualm, and I would say this even about Wynton, is that people are saying 'Here we are back in the tradition' and all that; when you think back to the major innovators who were strongly aware of their traditions too, but some part of their personality made them say 'Yeah, but I want to do it like this' or just 'Well, fuck it'. When I see somebody being too reverent about the past it makes me skeptical. And when I see somebody my age, or younger, or maybe just a few years older, playing as if they've never heard a note of rock & roll, it makes me wonder, where have they been? When I see somebody twenty years old with a suit and tie playing early Sixties and late Fifties music, well, it's puzzling.
"But one other thing I can attribute to Wynton's popularity is that his presentation is incredibly good. It's rehearsed, it's sharp, here's our tunes, bang, bang, bang and that's not just a small detail when you may be asking these days for people to shell out ten, fifteen bucks to get in. I'm aware that if a guy brings his girlfriend out to hear me, it could be a quarter of his income that he spends on that one night, and I ain't going to let that guy down.
"I know these times are rough. Also, in the Sixties, there were very few TV stations. Now there are sixty, broadcasting twenty-four hours a day. You're competing with that. There's less tolerance for unprofessionalism."
Hard competition is the characteristic of the era; Pat Metheny is too sharp an operator not to realize that it seriously affects jazz, as an art-form unpopular with much of the press and the broadcasting systems, and too ambiguous to be an attractive proposition to the accounts departments in the present climate. Standing as he does halfway between what's traditionally regarded as a minority interest and mass-appeal, Metheny views the current fashions as ominous.
"I'm intrigued by the rock & roll scene in the States at the moment. It's Prince and Madonna. Boy, that's a weird combination. This guy running around in his underpants and this chick talking like a virgin. I mean, what's happening? We play college gigs a lot, which used to be some of the best gigs, but now it's like playing for these pieces of jelly. They dig it but they're not really listening. A lot of the student community voted for Reagan in the last election.
"I'm as American as you can get, coming from the mid-West, but that's exactly where the real problems in America are building up - there's this lack of imagination and growing ignorance, Reagan keeps cutting the arts and education budgets and getting us involved in countries we have no business being involved in and we're growing this nation of stupid, prejudiced people."
Is it conceivable that the situation could sting this past- master of cool elegance into making a really angry record?
"Well, I'd be the first to admit that I have a kind of loose wire in this department, I definitely hear things funny. Jim Hall sometimes sounds angry to me. Some of the people characterised as really angry free players often sound totally passive and not very free. I had a group at high school that was tenor, guitar and four drummers that used to play Ayler and Ornette tunes and that was pretty angry at times. When people talk about Blood Ulmer, I say have you ever heard Hendrix or Sonny Sharrock? If you listen to 'The Calling' on the Rejoicing record, and turn it up as high as you can go, I think you'll hear what you mean in that."
And the future?
"I want to do a project with Milton Nascimento - he and Miles are it for me. And a solo project with some of these new guitars I'm working with. And surviving. Doing what I want to do, which is playing every night. When I wake up in the morning, I just thank my lucky stars. Some of the best players I know can't work."