Jan. 16 (Bloomberg) -- It may be an exaggeration to call ``Willie Nelson Sings the Blues'' a historic moment.

Yet the concert, held Jan. 12-13 at Jazz at Lincoln Center's Allen Room in New York, offered something rare: the country music star singing and playing guitar with the Wynton Marsalis jazz quintet, melding black and white, north and south, city and country. For two evenings, it all just became American music.

Marsalis and Nelson both look like they own the world. They are different worlds, of course, and you might have imagined conflicts. Yet they were both interested in the same thing, as it turned out: playing some old-time bluesy 4/4 swing. You could tell how well they were communicating by their eye contact, of which there was plenty, and by how much fun they seemed to be having. It was nice to discover that their worlds are, in fact, not all that different.

Marsalis's new-fashioned arrangements wove gently and effortlessly behind Nelson's innocent, carefree twang. Parenthetically, it should be remembered that Miles Davis was a Willie Nelson fan, and that he once recorded a tune called ``Willie Nelson.'' There's a gigantic picture window behind the bandstand of the Allen Room with a fine view of Central Park South, on which Davis lived toward the end of his life. As the evening wore on, the music seemed to become more in synch with the crosstown traffic, which was flowing smoothly.

Small Guy, Big Hat

The comfy Allen Room seats less than 500 people. All the sightlines are clear. Like many famous people, Nelson is shorter than you expect him to be, even in his ten-gallon hat. He lined up on stage as though he were just one more soloist with the band. He looked happy in that role. The difference between hillbillies and hipsters was split as they played such songs as ``Georgia on My Mind'' and ``Don't Get Around Much Anymore.''

Playing the guitar, Nelson has a touch of the raw, deliberate disorder of Thelonious Monk. He turns wrong notes into upper partials, and his time is sort of lopsided, like a child playing hopscotch. Occasionally he was flat, but he was just playing on the sad side of the note. He was the only musician on the bandstand not wearing a necktie.

Writing this in a hotel room, listening to Willie Nelson on earphones, I asked myself why I -- a jazz musician -- have dozens of tracks by Nelson and none by Marsalis in my iTunes file. I do not generally go out of my way to listen to Wynton Marsalis, and I can't really tell you why. With his assortment of mutes and plungers, he was certainly convincing with Nelson, and I may have changed my mind. In the past, he has aroused my admiration more than my emotions.

Divisive Definition

Marsalis is a showman as much as a musician, and he's really good at both. He's a fine trumpeter and a splendid front man, but he obviously has agendas other than the musical one.

Marsalis has been a divisive figure on the global jazz scene. Now the artistic director of Jazz at Lincoln Center, he defines the jazz tradition as something that stops at about 1960. This doesn't make him very popular in Europe, where musicians are more interested in being what they consider ``contemporary.'' Traditionalists, for their part, accuse the Europeans of trying to snuff out African-American history. The truth is, as always, more complicated than that.

In the Allen Room, it was a joyful joust. In between two songs, the black jazzman was telling the audience about how he and the white country singer had, during a rehearsal, discussed the relative merits of Louisiana barbeque and Texas catfish. (Marsalis is from New Orleans, Nelson from Abbott, Texas.)

Nelson just stood there and pretended to tune his guitar with his trademark aw-shucks smile as he listened to Marsalis's patter. Marsalis ended the story by saying, ``but Willie don't talk too much.'' Then he snapped the tempo for Clarence Williams's ``My Bucket's Got a Hole in It.''