THE KID From Brooklyn" was a 1946 Goldwyn movie in which, as it happens, Danny Kaye lampooned "serious" dancing -- among other things, he kidded Martha Graham "and her six little graham crackers."

The title of the picture, though -- which had Kaye in the role of a milkman turned prize fighter -- would seem a peculiarly apposite tag for dancer-choreographer Eliot Feld, who was not only for-real born in Brooklyn, but who also, to this day, pulls no punches.

He's 36 now, no longer the ballet wunderkind, but you'd scarcely know it from looking as his wiry figure or mischievous eyes. As an interlocutor, he's casual, brisk, cheery, charming. But there's a drop of acid in every grin -- he's got the good-natured belligerence one would look for in a wised-up, Flatbush Avenue police captain.

It's no surprise, then, that Feld made his first professional splash as a dancer at 16, portraying a teen-age tough in the original Broadway production of "West Side Story," and later in the film. Since he first created a ballet, however -- the memorable "Harbinger" in 1967 -- his reputation in this realm has grown so swiftly and steadily that there's no disputing his position as the most prolific and inventive ballet choreographer to have emerged in the United States after Jerome Robbins.

Feld was in Washington this past week to publicize the Kennedy Center debut of his company, the Feld Ballet, which begins a week of performances Tuesday night. The troupe -- the second Feld has fathered and directed -- was founded in 1974, and has performed at Wolf Trap every summer since then through 1978. Yet the Kennedy Center engagement will mark its first appearance in downtown Washington as a last-minute fill-in for the collapsed American Ballet Theatre season.

There's a real anomaly here, since the Feld company could accurately be described as the biggest little ballet troupe in the world, not only by virtue of its size (21 dancers) but also of the pungent, popularly flavored Feld repertory. The company is incidentally, one of the few classically based troupes anywhere to devote itself virtually exclusively -- more so, for instance, than in the case of Balanchine and the New York City Ballet -- to the work of a single director-choreographer. t

Feld has his own way of kidding dance, even though he may be deadly serious underneath, as will appear in his latest work, "Papillon," to receive its first local showing on opening night at Kennedy Center. Set to the only ballet score of Jacques Offenbach, the ballet will be one of nine -- all by Feld -- to be sampled during the week.

"You want me to tell you the cast of characters in 'Papillon'?" Feld asked with that loaded grin of his, discoursing on the upcoming performances. "Well, there are caterpillars, spiders, and butterflies, both babies and grownups. And the only male among them is Leopold, a lepidopterist. I suppose you could call it an entomological 'Giselle.' Yes, it's fairy-tale-like; it's the cold romantic notion, man in pursuit of idealized perfection. But it's romanticism with a difference. Remember my 'A Footstep of Air,' with its shepherd dreaming of his beloved -- only he gets dung on his foot. I mean, this is the 20th century, and it's hard to be from Brooklyn and pretend you're Byron. Where there's sheep, there's dung, and where there's dung, there's flies -- that's the reality, no matter how much dreaming you do."

Like most choreographers, though, Feld is loath to talk about the "meaning" of his ballets, except in rather general ways. "I find I only learn what they're about when they're finished and I've seen them whole, never while I'm doing them.

"My main concern, though," he adds, "is to do another ballet, the next ballet. I suppose I have some fears I'm going to dry up. Every time I finish a ballet, I go through a period of desperately waiting for another. And when it comes along, of course, I feel as if I'm starting from ground zero again. That's the agony and the excitement of choregoraphy. You're constantly being virginized. It's the only thing in life that does that to me."

"Papillon" is something of a departure for Feld, whose ballets over the past two seasons have all focused on a specific national ambiance -- Scotch-Irish highlands in "A Footstep of Air"; the American Southwest of cowboy lore in "Santa Fe Saga"; rural Mexico in "La Vida"; tourist Cuba of old in "Danzon Cubano," and the good ol' U.S. of A. of patriotic pageantry in "Half Time." (Feld is off on another new tack now, in a still-unfinished ballet to the music of Paul Hindemith.) "Papillon" is novel in another respect -- for the first time, the cast includes nine children from his recently established New Ballet School, whose pupils are recruited from the New York City public school system.

Though in earlier years Feld created pieces for such companies as American Ballet Theatre, the Royal Danish Ballet, the Joffrey Ballet and the National Ballet of Canada, nowadays he's less and less inclined to work with any troupe other than this own.

"It has a lot to do with the reasons I left ABT," he says, referring to the company for which he danced and choreographed, on and off, for eight years. "The trouble with the big repertory ballet companies -- they're great, don't get me wrong -- is that there's so many people competing for money, time and dancers that the fight becomes debilitating after a while, when you're trying to get something done.

"Besides, I have this theory that if you give any ballet in a repertory company enough time, it'll come out looking like 'Swan Lake.' There's this homogenizing that takes place."

Feld has another theory that there's a danger of rigidity in the comtemporary emphasis on preservation of dance masterworks, old and new, through film and notation records.

"You know," he says, "If we could have seen the original Swan Lake' as it was first created, it might not be alive today. The stars today wouldn't have their virtuoso vehicles, and the whole thing might look very stodgy to us. The great thing about the classics has been their ability to be molded with the times, to change and yet remain fundamentally what they were. By the same token, I bet Nijinsky would be nowhere near the myth he now is if we had films of him to look at, if he had to be judged by modern standards. He wouldn't have that precious anonymity, or the same mystique. I have to admit that when I see Misha Baryshnikov dancing in 'The turning Point,' I'm grateful we've got that captured for posterity. But of all we know, in 30 years maybe all dancers will move and look like that -- I don't really believe it, but I don't have the perspective of 30 years from now."

The Feld company has just returned from a tour that included Paris and Italy -- it was something of an eyeopener for Feld. "The Parisian critics took an acute aversion to 'Half Time' (set to marching music by Morton (gould, it's peopled by drum majorettes, pompon girls and bandmasters). Maybe it was a mistake to do it there -- the piece just doesn't have any of the resonances for the French that it has for us. But it's weird -- here at home, I'm accused of ridiculing patriotism; there they thought it was all just a lot of flag-waving!"

A prime source of excitement for Feld these days is the New Ballet School, which began operating in 1977 under Feld's auspices. "Two years ago," Feld relates, "we acquired beautiful, spacious studio quarters in downtown Manhattan, and I began to look around for a way to train dancers professionally using this space. Then it occurred to me there's a tremendous untapped resource in New York -- over a million public school children. We had talks with the Board of Education and developed a program in which we'd audition kids 7 to 11 -- they provided the bus transportation, and we'd give tuition-free instruction." The school has auditioned more than 8,000 children by now, of which some 400 have received training -- it's from this group that the youngsters participating in the Kennedy Center performances of "Papillion" have come.

"The amount of talent we've found is extraordinary," says Feld. "And the wonderful thing about it is that 80 percent of the school population is nonwhite; up to now, ballet dancing has been almost excusively a white, middle-class phenomenon."