NEW YORK -- The question is, what makes a Jule Styne song recognizably a Jule Styne song?

You wouldn't think this a simple point, there being close to 2,000 such songs, but the composer answers promptly. "It is simple and harmonically attractive, that's the Jule Styne signature," he says. "Simple and harmonically attractive."

And what, exactly, does "harmonically attractive" mean?

"Beautiful chord formations. I'm using Cole Porter's words -- he said 'Just in Time' was the most harmonically attractive song he ever heard."

Styne, who will be 85 on New Year's Eve, hesitates only for a second as he rises from his armchair and crosses to the Steinway in a corner of his living room. "The average songwriter," he announces, tossing off a few chords, a brighter and bouncier version of "Just in Time." And then he plays it the way he wrote it for "Bells Are Ringing" in 1956, a few octaves lower with a darker, more yearning tone, a lovely thing. Who's going to argue with Cole Porter?

If Jule Styne were a jukebox, which he sometimes seems to be, you could push hundreds of buttons and hear the hits. Memorable melodies would pour forth, tunes composed for scores of movies and Broadway musicals both forgotten and immortal, songs that made stars of their singers.

You could select his very first hit, "I Don't Want to Walk Without You, Baby," from a 1941 Paramount picture called "Sweater Girl." Or a cowboy number called "Purple Sage in the Twilight," written for Gene Autry back when Styne, who grew up in Chicago and wasn't quite sure whether sage came in purple, was scoring westerns on an oat-strewn Hollywood lot. Maybe one of the classics written for his beloved Sinatra, with lyrics by Sammy Cahn, like "Saturday Night Is the Loneliest Night of the Week" or "I'll Walk Alone" or "I Fall in Love Too Easily." Or "Three Coins in the Fountain," which won the Oscar in 1955.

A comprehensive Stynean jukebox would include season songs, like "The Things We Did Last Summer" and "Let It Snow, Let It Snow" and "The Christmas Waltz." It would stock all 50 recorded versions of "Just in Time" (Sinatra, Tony Bennett, Mel Torme) and the 80 versions of "Time After Time," up to and including Placido Domingo's. Most important, you could put in your quarter and hear one of the musical theater scores that have kept Broadway humming for more than 40 years: "High Button Shoes," "Gentlemen Prefer Blondes," "Bells Are Ringing," "Gypsy," "Funny Girl."

And maybe a few more to come. Recipients of the Kennedy Center Honors, bestowed for a lifetime of artistic accomplishment, are presumed entitled to rest on their laurels; they're not required to be plugging away at new projects. But Jule (pronounced JOO-lee) Styne always is, with the same restless vigor that's kept collaborators hopping since the days of singing cowboys. The latest score on the Steinway is an adaptation of "The Red Shoes," the film that inspired a million little girls to study ballet.

"It's remarkable; I forget he's 85," says Ken Ludwig, the "Lend Me a Tenor" playwright, who's writing the book. The first time they met, Ludwig had made plans to see a show after a day spent working together nonstop. "Why don't you come back afterwards and we'll have a drink?" Styne suggested, as Ludwig prepared to leave at 6. Ludwig pointed out that it would be 11 p.m. before he could leave the theater and arrive at Styne's Fifth Avenue apartment, but his new partner was unfazed by late hours.

"So I get to his place and he's all ready to go: 'C'mon, let's go to Elaine's,' " Ludwig reports, still sounding unnerved. "We jumped in a cab, we ate fried zucchini all night and talked about the show till 1 a.m."

Maybe the reason Styne still revels in the Broadway theater is that it took him so long to make his way there. "I started to write songs late in life," he says, a dapper figure in a blazer and tie and a striped shirt with an immaculate white collar. His loafers gleam. "I had bands, I was a great vocal coach. When I started to write songs I was about 36.

"All the people being honored {at the Kennedy Center} were already stars by then," he points out. "Katharine Hepburn was a star; Billy Wilder had already directed many, many pictures; Rise Stevens had sung many an aria." But Styne was a novice -- "I was just hoping I would be good" -- and he was stuck, worse luck, in Hollywood.

However many wonderful songs came out of his years under contract to various studios, Styne was chafing. "I found that Hollywood was no place for anyone who really wanted to create," he says. "You were beholden to the producer and director. They had the right to change notes, to take a song out, to use half a chorus." Half a century later, he can still get indignant about his treatment. "Am I glad I ran away from that place," he says. "I came here to write for the theater."

Theatrical composers, though Styne despaired of being one until "High Button Shoes" connected in 1947, get more respect and more control. Arthur Laurents, who wrote the book for "Gypsy" and directed the current Broadway revival, remembers Styne's insistence that the ballad "Little Lamb" not be cut as the overlong show was trying out. "He said, 'If you cut that I'm withdrawing my entire score.' He said it quietly and with great dignity. And the song stayed."

"It stands," Styne says of a theater score. "You take the raps, you get the applause. It's the only pure way ... a wonderful art form, to go in and enjoy the movies, but not for people who want to be remembered."

It may be for "Gypsy," more than any other single work, that Styne will be. Laurents thinks it's his best score, and Styne points to it as a prime example of the way a theater composer has to learn to be a dramatist. At least, that's an approximation of what he says.

A subject that excites him can trigger a burst of nonsequential speech, with one idea detonating another, that lyricists Betty Comden and Adolph Green once dubbed "Stynese." What Styne actually says about "Gypsy," in Stynese, is: "It's like {New York Times critic Frank} Rich said: 'Gypsy' is the 'King Lear' of the musical -- in other words it has the drama of -- it has more -- it's gone over the brink. That's where we are. And mind you, it was written 34 years ago, but he says it's the 'King Lear' of -- it has the power, it -- forever! Well, you learn that."

The rhythms of his speech "will tell you everything you need to know about his character," says Stephen Sondheim, who collaborated with Styne on "Gypsy." "In the middle of every sentence he has another thought and then another. You ask him a question and five minutes later you'll come out of the tunnel and he's talking about Ethel Merman. A tumble of ideas."

There's a wealth of melodies up there in Jule Styne's head too. "I could sit down right now and write 100 songs, right here sitting with you," he says. He doesn't quite know where they come from, but they materialize so obligingly when needed that he can be profligate with them. "I think he sweats melodies; they pour out of him like sweat pours out of other people," Laurents says.

His collaborators invariably notice that when there's a minor problem with a song, Styne would rather ditch it and write an entirely new one than tinker. "He comes in next day and tosses the sheet music at you and says, 'May I say, another hit,' " Laurents says. "And it usually is."

However, "Kern was the same way," Styne responds when this habit is pointed out. "Refused to change a note." He knew Jerome Kern, of course; Styne was a member in good standing of the Monday Night Music Club -- Harold Arlen, Hoagy Carmichael, Ira Gershwin, several others -- which met monthly in Kern's living room.

Styne's a prodigious name-dropper, less out of pretension than familiarity: He simply knows everybody. He chatted with Hepburn at the memorial service for Irene Selznick. He told Leslie Bricusse, who dropped by recently, that he'd better move to New York if he wanted to write hits again. Darryl Zanuck personally supplied Styne's favorite put-down of Lotusland: "He told me that Hollywood was a land of proven failures. One of the greatest lines of all time." And his practice of not composing at the piano was inspired by no less than Sergei Rachmaninoff, who lived across the street from Styne in California. "Because if you write at the piano," Rachmaninoff cautioned, "the song can only be as good as you can play."

It's a long honor roll, the friends of Jule Styne, covering a long stretch of theatrical history. Some of its members are gone, and some of the traits that marked a younger and rasher Styne have been shed with the years. So fond of women that his own son affectionately nicknamed him "the playboy-composer," Styne had a roadshow romance with Constance Bennett, a fling with the young actress who first played Gypsy Rose Lee, and various other amours, many of them recounted for his biographer, Theodore Taylor. But Styne's second marriage, to Margaret Brown, an actress and model three decades his junior, has lasted for 28 years.

Gone too is the gambling fever that nearly ruined him. Styne's debts to bookies and to the IRS ran into the mid-six figures at one point, draining most of his profits from "Gypsy" and other moneymaking projects. One of the reasons he worked so feverishly, Taylor's 1979 biography makes clear, was to stay ahead of the thugs and the tax collectors. Now it's a closed chapter; Styne no longer even wagers a few bucks at the off-track betting window.

"A good friend of mine, Martin Gabel, we used to go to the races all the time," Styne says. "When he passed away, I lost interest in the whole thing."

What endures, of course, is his work and his undiminished devotion to it. "Do you like music?" Styne asks, suddenly sounding a bit shy. "Would you like to hear the ballad from 'The Red Shoes'?" He heads back to the piano bench.

The song has that harmonic attractiveness, all right, with a bittersweet undercurrent. You can almost hear a slinky singer in black, eyes closed, wrapping herself around a mike stand to deliver it in some hushed cabaret. Styne is very happy with it.

It has a title -- "You Were Always There" -- but no words as yet. Lyricist Barbara Schottenfeld, "a great, great talent," hasn't gotten to it; she's been involved with a show of her own, and it's just closed. And who could be more sympathetic, and give more useful advice, than Styne?

"Darling," he told her, "I've had so many flops. Sure, I cried. I jumped out of windows. But then, by the end of the evening, I just say, 'Next?' "