Gary Burton rounds out a half-century career in American jazz Friday at the Jazz Kitchen

 Because personal expression, involving composition on the spur of the moment, is essential to jazz, people like to claim a

Makoto Ozone and Gary Burton are touring together for the last time.

certain honesty is basic to the music.

Where that is most questionable may lie in the difficulty about being honest about aging. Jazz shares in common with other forms of entertainment a strong reluctance to leave the scene. I recall Dizzy Gillespie shaking a "rain stick," hitting the floor with it while doing simple dance steps, at Clowes Hall; all he could do with the trumpet was puff a few woolly notes at a time with his bell into the microphone. Quite a falling off from his quondam brilliance!

Gary Burton remembers seeing B.B. King toward the end of his life: "I loved him dearly. It was a sad evening and he was a shadow of his former self." And Lionel Hampton, the jazz pioneer on Burton's instrument, the vibraphone, was so afflicted with arthritis late in his career that he barely showed what he was known for, Burton remembers.

That route is not for Burton, the Indiana-born four-mallet genius, who is nearing the end of a half-century career. Born in Anderson 74 years ago, Burton got a national reputation as jazz was challenged by the dominance of rock in the late 1960s. He maintained that career through many years of being heavily involved in jazz education. Now, with longtime collaborator Makoto Ozone at his side, he's wrapping things up.

Two shows at the Jazz Kitchen Friday evening will constitute his last American engagement. Then he will travel to Japan, Ozone's homeland,  for 10 concerts that were set up several years ago, before Burton decided to retire. Speaking last week from New York City, where the last U.S. tour was under way, Burton told me: "I don't want to become one of those aging musicians who keep on playing past their peak," he said, adding: "There is little to no precedent for retiring."

He was keenly aware of the norm for many years before he came to a different conclusion. After a major heart operation four years ago, he started noticing the decline in his musical gifts. The first to go was his perfect pitch, the relatively rare ability to identify any note by letter designation upon hearing the given frequency for that note. He had had it since he was 6, and suddenly it was gone. Then there was trouble sight-reading (being able to play a piece of written music at sight), followed by difficulty memorizing, a core skill of jazz musicians.

"It started to happen frequently when I was playing," he said. "I'll forget where I’m at in a song, and it'll take a few seconds for me to get back where I should be. I’ve had a handful of these calamities and it unnerves you, shakes you up. It was a new issue to deal with, and it was time for me to know when to step back."

He had retired from the Berklee College of Music in Boston, after more than 30 years as faculty member and administrator. He continued to do some coaching and master classes, and the performance worries carried over to his teaching: "I had to make lists of what to talk about," Burton said. "The concentration thing started to be happening."

Burton enjoyed a stellar performing career, attracting notice when he was still in his teens. In his early 20s, he recorded an album titled "Duster," which represented the genesis of jazz-rock fusion. The late guitarist Larry Coryell joined him in the front line, with Steve Swallow on bass and Bob Moses (for the recording, Roy Haynes) on drums. It was that group I heard in 1967 in one of my first visits to a jazz club, the Club 47 in Cambridge, Mass., just a few blocks from Harvard Square. Its music policy also leaned toward folk: Joan Baez and Tom Rush got their starts there.

The Grammy-winning vibist also collaborated with Keith Jarrett, Stephane Grappelli, Carla Bley, and Chet Atkins early in his career. Later associations with Argentine tango composer Astor Piazzolla and versatile guitarist Pat Metheny have also been notable milestones. His association with Ozone goes back 35 years; the other pianist most frequently represented on his recording and performing schedule has been Chick Corea.

Burton makes this comparison: "They're very different, so there's different material. Makoto and I play a much wider array and types of music; we play old jazz from the 1930s, classical pieces. I’ve never played with anyone who has so much range, so we can explore together." After his Berklee years, Ozone joined Burton's band in the 1980s. Since then, the Japanese pianist has settled down in Japan, and has also concentrated more and more on classical music. He had a three-week window in his schedule to join Burton in the U.S. before the Japanese tour wraps things up for Burton. He says he plans to drop music for good; he has no desire to continue playing or teaching privately.

Asked what he wants to be remembered for — and he certainly will be remembered — Burton identified several things: the four-mallet technique, "blending popular music with jazz," and playing concerts as a duo: "It was a rare thing when Chick and I started playing duets....Those are some things I'm proud of."

In the course of his multifaceted career, Burton has been impressed by the spread of jazz throughout the world. "When I started, the majority of the audience was American and in the big cities," he noted. Similarly, jazz education has spread all over the world. When he started out, the American options for academic jazz numbered two: North Texas State University and Berklee.

Being part of such a global scene makes bringing it all back home all the more special, he said.  "I feel this is the end," said the vibes star, who now lives in Fort Lauderdale, Florida. "The U.S. is the part of the world where I play the most. I started out in Indiana and I’m coming back."

And he'll be able to say he kept his honesty — on and off the bandstand.