In 1983, Dick Hyman supplied the music for “Zelig,” Woody Allen’s film about the “chameleon man” who could change his identity at will to conform to his surroundings. Certain similarities between Zelig and Mr. Hyman are hard to miss. In his various roles as a pianist, arranger, composer, and a producer of concerts and recordings, Mr. Hyman can recreate any musical style imaginable, from Scott Joplin to Lennie Tristano. As a studio house musician in the late 1950s, he played keyboards on many early rock ‘n’ roll hits, including the original version of “At the Hop.” And he can also knock out some mean Bach, both on piano and pipe organ.

It was in 1985, two years after “Zelig,” that Mr. Hyman first put together a series of July concerts at the 92nd Street Y. He had become friendly with the Y’s producer, Hadassah Markson, when he played ragtime piano for a concert in the Y’s long-running “Lyrics and Lyricists” series.When she initially proposed a series of concerts at the end of July, he had his doubts. “I thought, ‘But there’s no one in New York then,'” he said. “But her idea was to have them on Tuesdays,Wednesdays and Thursdays, before everybody leaves town for the weekend.” That first season served as a test, and 20 years later the concerts continue to sell out almost every night.

This year’s “Jazz in July” performances, which run Tuesday through Thursday both this week and next, will be Mr. Hyman’s last. The series has not only provided hours of great entertainment but over the course of its existence has become an essential part of the jazz repertory movement and, like Mr. Hyman himself, a New York institution. I sat down with Mr.Hyman last Friday to talk about Jazz in July, his long career, and what the future holds for him at age 77.

Mr. Hyman started, like nearly all pianists of the era, with the European classics (he did, however, win a radio contest that gave him 12 lessons with the great Teddy Wilson). A child of the swing era, he went in 1937 – he was 10 – to the Paramount to hear Benny Goodman and His Orchestra. “Then my older brother started coming home with these new things called jazz albums, and that was the first time I heard the music of the Jazz Age. I fell in love with Jelly Roll’s ‘Red Peppers,’ Louis Armstrong’s ‘Hot Fives,’ and Bix Beiderbecke.”

Already a professional pianist, Mr. Hyman served in the U. S. Navy during the final months of World War II.When he got out, in 1946, he was just in time to catch the final glory years of the 52nd Street scene. Swing Street, as it had been known, had already begun its descent into a series of strip-and-clip joints.”I had only one major gig on the street,” he says,”but it was accompanying ‘Zorita and her Serpent.’ “

In the current era, student jazz mu sicians – a concept that was unknown when Mr. Hyman was coming up – are taught to appreciate and improvise in different jazz genres, such as Dixieland and Bebop. Things were completely different in the period when Mr. Hyman first began playing piano professionally.

In the 1940s in New York, there were supporters of Eddie Condon on one side and of Charlie Parker on the other; a third contingent insisted that the only pure jazz was made by New Orleanians who, at 40 or 50, now seemed like ancients. Rather than working together, the various factions could at best agree to disagree with each other, and much of the critical writing of the period consisted less of appreciation than what amounted to arm-wrestling.

At this time Mr. Hyman was, he says, “A die-hard Condon-ite,” but when he first heard Charlie Parker and Dizzy Gillespie,”I saw no reason why I couldn’t incorporate Bebop into what I was already playing.” Mr. Hyman was on the bill alongside Parker, Lennie Tristano, and a pre-calypso Harry Belafonte when Birdland opened its doors on December 15, 1949 (he was a member of Dixielander Max Kaminsky’s band). He later served as that club’s house pianist, working with Lester Young, Hot Lips Page, and others. In 1952, he played with Parker himself in a television clip that has been shown thousands of times in any number of documentaries.

By the early 1950s, Mr. Hyman had established himself as a studio player of rare versatility. “It may sound like I’m being over-modest, but that really wasn’t a big deal then.” He points out, “You can’t imagine it today, but there were hundreds and hundreds of studio sessions then, not only record dates, but soundtracks, jingles, television and radio broadcasts – you name it. All you had to do was read well and be willing to play anything, and you started getting calls.”

Mr. Hyman spent most of his working career in the recording studios, doing more sessions than even a team of discographers could keep track of, as well as several Broadway shows (most notably “Sugar Babies”) and contributing to more than 40 films in capacities ranging from orchestrator to composer to pianist to conductor. But though he made his first solo session in 1950 for a 78 label called Relax Records and recorded prolifically as a leader in the 1950s, Mr. Hyman didn’t really assert himself as a star of the jazz world until the 1970s.

Today he estimates that he has released approximately 150 albums un der his own name, with five coming out this summer alone. (The most notable is “If Bix Had Played Gershwin,” just released on Arbors Jazz 19283, a set of duets with trumpeter Randy Sandke. Mr. Hyman is one of the great advocates of the trumpet-piano duo format).

In 1973, Mr. Hyman worked with George Wein in the New York Jazz Repertory Concert, an organization that became the forerunner of the jazz repertory movement. Its spiritual offspring include such institutions as Gary Giddins’s American Jazz Orchestra, the Smithsonian Jazz Orchestra in Washington D.C., and Jazz at Lincoln Center. “Bach and Mozart are still alive and well in the classical world,” says Mr. Hyman. “They’re long dead themselves and we don’t write like that anymore, but we still can perform that music and enjoy it.The same can be said for Duke Ellington, Louis Armstrong, and Bix.”

Even though Mr. Hyman frequently presents newly written music, like this year’s “The Longest Blues in the World,” the focus is on jazz history, with the emphasis on the Hot Jazz of the 1920s and 1930s and the Swing era of the 1930s and 1940s. But the programming sometimes extends even earlier (to New Orleans and Ragtime) and later (to Bebop and occasionally even free improvisation). “After 20 years, I’ve built up a lot of trust with the audiences there,” he says. “They know me and my taste well enough to pretty much go with whatever I want to give them.”

So why step down now? “This is the most fulfilling and pleasant project I’ve ever been involved with,” Mr. Hyman says, “but 20 years is an appropriate time. I’ve been around on a wonderful carousel ride 20 times now.” He says he will continue to do the Y’s three-concert spring piano series, as well as other events around the country (such as the Oregon Festival of American Music). And the 92nd Street Y will continue with Jazz in July next year, though it remains to be seen whether it will be produced by a single person or use a sequence of producers working on individual shows, as “Lyrics and Lyricists” now does.

Whatever the case, Mr. Hyman promises that Jazz in July will continue to represent the diversity of American jazz. “I disapprove of segregation in any form,” says Dick Hyman,”and to me the face of jazz mirrors the face of the American people.”