Pat Metheny's current project -- recording and touring with saxophonist Ornette Coleman -- won't surprise those who've followed the guitarist's career, since he's often performed Coleman tunes in concert. In fact, the roots of this seemingly incongruous collaboration between a musician known for his melodic, lyrical playing and another known for his fractious, challenging "free" improvisations go back almost 20 years to a record store in Metheny's Missouri hometown.

"I can remember hearing my first Ornette record when I was 12," Metheny recalls. "It was almost accidental how I encountered him in the cut-out bin. I bought that record, probably along with the Dave Clark Five and the Beach Boys, and took it home not really knowing what it was. As far as I knew, it was a new rock band. And something about it just knocked me out, hit me -- these guys are having some fun and they're playing this hip thing.

"At that point I hadn't really started playing the guitar or thought about being a musician. But as soon as I started, some of the first tunes I learned were those Ornette heads. They just always sounded happy to me, and very melodic. In some ways, he's the most melodic improviser around, it's just that he doesn't do it in the context that we're used to hearing.

"As the years have gone by, I'm much more open as to what could conceivably constitute a melody. Ornette doesn't try to be melodic, he is. It just comes out that way. He's created his own dialect."

Because he was such a fan, it seems inevitable that Metheny would some day play with Coleman, who set the jazz world on its ear 25 years ago with his free-playing concepts and confused it further with his complex "harmolodic" theory. The seeds were sown in 1981, when the guitarist teamed up to record and tour with bassist Charlie Haden, saxophonist Dewey Redman and drummer Paul Motian, all Coleman alumni. Coleman came to hear them and suggested that somewhere down the line there might be some shared energies.

The opportunity came when Metheny signed with Geffen Records (after a decade with the German jazz label ECM) and was given a production contract that offered total freedom. The resulting "Song X" may not be standard Geffen fare, but it's already racking up impressive reviews and solidifying Metheny's reputation with jazz traditionalists who have in the past dismissed his "progressive" position.

"Song X" is a long way from the pastoral textures that "define a big part of my philosophy," Metheny admits. "I'm very texturally oriented and I enjoy playing pastoral kinds of things . . . but I don't see that feeling being that different from the feeling that's on this record. It's a different kind of texture, but it's not a different kind of feeling, just a different slant on the same thing."

Metheny remembers the first rehearsal with Coleman. "The first note Ornette played on his horn was a concert A, and the first note I happened to play was a concert A, a perfect unison." That may have been the first and last unison playing they did, but the empathy and communion among the players (who include Haden and drummers Jack DeJohnette and Denardo Coleman) is as evident as it has been for years between Metheny and the Group's keyboard player, Lyle Mays.

"We felt it was important to try and come up with an alternative vocabulary and to address the issues we were going to be faced with as improvisers from a different angle, rather than trying to recreate his or my groups," Metheny explains. The specific question was "whether we were going to play individual solos, one after the other in the old way, or as in [Coleman's current electric band] Prime Time, where Ornette basically puts the horn in his mouth at the beginning of the tune and takes it out at the end, with no 'solos' per se."

They settled on a middle ground. "There's a lot more actual interplay here, moments where it's hard for even me to tell who's playing what. That was a specific goal" -- as was Metheny's fitting into the long-established harmonic intimacy that exists between Coleman and Haden.

"The thing that happens between the two of them is absolutely unique," Metheny says, "and the challenge for me was to try and find a third line. No one has really tried to comp behind Ornette in the traditional jazz way and it's very difficult to do because he doesn't play chords. That's the wildest thing about what he does. And that's something I'm going to be working on for years, trying to figure out how to play diatonically to a major scale and never play a chord . . ."

Still, Metheny adds, melody is the most important thing for him. "It doesn't matter if I'm going to play in a situation like this that's very dense, or whether I'm going to play a ballad with my band that's very open. I want to make the melodies that I play have a weight to them that's more than the note. Even on the tunes that are really moving pretty fast, I think that we came close to getting that feeling in the ensemble."