John ABERCROMBIE cherishes the advice given to him by Gil Evans. The New York-born guitarist, who makes a rare professional visit to Scotland this weekend - he's been here more often as a tourist investigating family roots - had been talking to the great orchestrator and Miles Davis collaborator about his frustration at not being able to play certain styles of music better when Evans stopped him and said: "Be yourself."

It's advice that Abercrombie clearly took to heart. In a career that his oldest fans will trace back to the jazz-rock band Dreams of the late 1960s and includes a wealth of recordings, many of them featuring in a 37-year relationship with the prestigious German label ECM, Abercrombie has only ever sounded like Abercrombie. He hasn't always attracted the attention he deserves but without his influence better-known players such as John Scofield and Bill Frisell wouldn't sound the way they do.

"Gil's contention was that to be well-rounded was to be mediocre," says Abercrombie. "He felt that if you tried to play like everybody else, you'd become a jack of all trades and master of none, as the saying goes. His example, of course, was Miles Davis, who couldn't play the high notes that Dizzy Gillespie could play and wasn't a great master of the trumpet like Dizzy or Clifford Brown or Fats Navarro. But Miles developed his own way of doing things - his approach was more that of an artist than a musician in many respects - and that's why his playing and his sound became so personal."

Evans wasn't the first person to encourage Abercrombie to find his own voice. Having picked up guitar as an Elvis and Chuck Berry-inspired teenager in the 1950s, he arrived at Berklee School of Music in Boston straight from high school in 1962, thanks partly to having heard some jazz courtesy of Dave Brubeck and Barney Kessell and partly because he didn't really know what else to do. It also helped him avoid being drafted into the army and shipped off to Vietnam.

"I was pretty naïve musically at the time and didn't really have a clue about playing jazz, but Herb Pomeroy, who was pretty much Mr Berklee in those days, was very strong on not having students imitate other musicians," he says. "That's changed, I think. Now students are made to transcribe hundreds of solos from records and regurgitate them, whereas we might lift a solo here and there and then use it as a stepping stone to something of our own. I was five years at Berklee and it was only really latterly that I began to feel confident as an improviser."

Much of this slowly growing ability was gained from learning on the job and from the inspiration of seeing and hearing jazz giants including John Coltrane and Thelonious Monk at close quarters. One of the gigs that allowed Abercrombie to grow was in a lounge bar where he was playing background music - and so could play whatever he liked - that happened to be owned by the people who owned the jazz club next door.

The two premises shared a kitchen, so during his breaks Abercrombie could pop through and hear his heroes. When the Brecker brothers, Randy and Michael, were in town with Horace Silver, the reverse applied. They happened across Abercrombie during one of their breaks and invited him to New York to audition for Dreams. Abercrombie then moved on to organist Johnny "Hammond" Smith's band, when the onstage jazz training really got serious, and then on to Chico Hamilton, Gil Evans and Gato Barbieri before reuniting, in 1974, with Dreams' drummer, Billy Cobham, who by this time had made his name as part of the first incarnation of the Mahavishnu Orchestra.

With Cobham, Abercrombie played loud, feeding his guitar through a "monolith" of a reverb system. The volume came down, though, when he began recording regularly for ECM, as a leader and on sessions with musicians including saxophonist Dave Liebman and drummer Jack DeJohnette, with whom he went on to form the trio Gateway, which also featured bassist Dave Holland.

"It's impossible to say what would have happened had I not got involved with Manfred Eicher at ECM," Abercrombie says. "I owe him a lot. It was through recording with him that I started to compose my own music, and the way I sound now, although I suppose in a way it was really emphasising how I sounded anyway, is really down to hearing myself clearly in the studio for the first time with Manfred. I'd listen to the records and think there must be a way of replicating that sound onstage'. It took a while but the set-up I use now - two amps for stereo sound and a small effects unit so it's there if I want it - is the one I've been happy with for probably 20 years."

Although he played at Glasgow Jazz Festival with Gateway in the mid-1990s, Abercrombie hasn't toured Scotland since a decade before that, in his duo with fellow guitarist Ralph Towner, an event that's remembered, in Glasgow at least, for a punch-up between the chatterers and the listeners. The setting that brings him back, saxophonist Julian Arguelles's trio, is likely to be similarly intimate.

"I'm really looking forward to it because Julian and I have only ever played together in other people's bands so it'll be good to get a chance to work more closely with him," says Abercrombie. "I still like to play new music, although a lot of the work I do tends to be with musicians I've established quite long relationships with, and I still like a challenge - as long as it's not too much of a challenge. I'm happy to work in different areas of music, be it orchestral or ethnic, but I prefer to keep it simple because, that way, you can keep the essence of what you do intact."

The Julian Arguelles Trio with John Abercrombie plays Glasgow Royal Concert Hall tonight; Redrooms, Perth, May 4; Queen's Hall, Edinburgh, May 5; Eden Court, Inverness, May 6; Lemon Tree, Aberdeen, May 7; and Byre Theatre, St Andrews, May 8