First-rate talent is turning up in Washington galleries this season, in no small part because of a proliferation of new dealers, most of them young and smart, and all aiming to ferret out and promote every good artist living within eyeshot. Three outstanding current shows in the new-breed galleries make the point.

"I think Washington artists are spoiled," says Louis Andre proprietor of the Wolfe St. Galleries of Alexandria and Georgetown. "Any good artist who wants to get a gallery show here can do so, and there are untapped collectors here who will buy." Andre discovered his best-selling artist. Tom Dineen, in a show at the Alexandra Art League five years ago and has been "selling everything he makes" ever since. Half of the current show of Dineen drawings at Wolfe St. Georgetown, was sold before it opened.

Painter Jerry Clapsaddle, who came from upstate New York to teach at the University of Maryland last year, is among the increasing number of artists moving to Washington to take advantage of precisely the situation Louis Andre describes. "This is the first city I've ever been in where a dealer asked to see my work, instead of the otherway around," he said "In New York you might have to wait years for a show. Here, i met Max Protetch at a party one night he came to see my work the next day and he gave me a show one month later. "Clapsaddle is currently having his second show in one year at Protetch-McIntosh."

This is a recent and radical change in the Washington artists condition, as attested to by Jennie Lea Knight, who after 20 years of working and exhibiting her wood sculpture in Washington has been rediscovered by a new champion, dealer Diane Brown, now beginning her second season on P Street. Brown coaxed Knight into her current show, and with good reason, for it establishes her incontrovertibly as a sculptor of the first rank. (A show of her printings will follow in November.)

Though her name has a familiar ring around town, Jennie Lea Knight, 44, has kept one of the lowest profiles in recent Washington art history. One of a handful of graduates of the Institute of Centemporary Art here, where she studied with Ken Noland (she was 15), Knight opened the Studio Gallery and Art School in Alexandria at 23. She continued to teach and show there until 1964, when she gave the gallery to the participating artists, who turned it into the city's first coop.

Knight joined Jefferson Place gallery in 1964, which might have made her reputation, except that she was overshadowed by the company of older superstars like Noland, and contemporaries like Sam Gilliam. Her work, too, was often out of sync with the stylistic preferences of the time. She was making round, sensuous volumes of wood when New York was brandishing vacu-formed plastic and polished steel.

Bad luck played an additional leitmotif : Just before a show at the Phillips Collection in 7319, her studio burned down. Jefferson Place folded the same month. Knight subsequently had what she calls a "dry spell," and has not had a major exhibition since.

If Knight was out of step before, she has surely picked up the beat of '70s in her current show, or perhaps the art world has picked her beat. What she does in these smallscale, non-figurative wood sculptures in combine natural forms, like thin, fragile tree branches stipped, smoothed and carved, with man-made forms such as laminaed or milled wood. One could see in them the symbolic melding of '60s coolness with '70s warmth.

The results provide an extraordinary wide expressive range, from an amusing, light-hearted work like "Zig-Zag" or "Climber" to the sensuous, brooding "Nester," a hollowed-out burl. Her ability to speak through line is seen both in the sculptures and in the spare, summary drawings of her rural surroundings. It is a show not to be missed, if only to see what some of today's most intelligent and original abstrat sculpture looks like.

Jerry Clapsaddle's paintings at Propetch-McIntosh are also very much of the 70s, in that they represent similar reunion of expressive, organic forms with the formalist ideas of '60s abstraction. Like so many of his contemporaries. Clapsaddle eschews the intellectually tough but emotionally cold and vapid "corporation art" (his words) of the '60s.

Clapsaddle starts with a grid, over which he paints layers of deliviously colored marks, which read as an all over pattern. Having established this background, he then begins what he calls " the real painting," the amorphous areas of denser painting which appear as "eminences," or expressive presences. In this series of work, called "Tributes," very specific "presences" are named in the titles, such as "Piaf," which is endlessly evocative, to the tear-like drips of paint at the bottom.

In Clapsaddle's best work, "McDonough's Cloak" and "Tiraz," the paintings become more enticing the closer the viewer gets, with new and luscious patterns and colors emerging as others dissolve. Beware of getting too close, however. This is the sort of painting you're apt to want to take home.

Tom Dineen's 30 large and gigantic charcoal and pastel drawings at Wolfe St. Gallery, Georgetown, are out of an entirely different aesthetic, almost insistently early 20th-century European in essence and feel.

Dineen, a gifted and prolific artist who seems to shift effortlessly from painting to drawing and from style to style, began this cycle of basically black and white drawings during his most recent visit to the MacDowell Colony in New Hampshire, one of the many awards heaped upon him during his remarkably successful five-year-old career in Washington. The best works on the view, however, were completed since his return.

The show is hung so that the viewer can see how the cycle developed, beginning with four drawings of distorted human forms in the Francis Bacon manner (with erotic overtones), and becoming more interesting as the human references become less obvious and are swallowed up in darkness. As the series progesses, the biomorphic forms increasingly are balanced by the overlay of geometric elements - lines and circles. The series culminates in drawing No. 28, where everything is knit together in a sleek pictorial balance.

The question one must consider here is, "so then what?" Do these works say anything at all beyond the fact that Dineen can make razzle-dazzle drawings with flawless compositions? There is a certain mystery implied by the darkness, but is it enough merely to be mysterious."

Deneen at 31 seems aware of the danger and the need for more challenge. That may be behind his talk of going to New York "to lose himself again." For an artist with his great gifts, more challenge would seem a very good idea indeed.