THE SILENT Clowns," which begins a three-week stand at the Key in Georgetown this Wednesday, promises to the an exceptionally satisfying revival series. Few forms of moviegoing are as enthralling as the spectacle of the greatest silent film comedians in their prime. The management of the theater also hopes to present them in a setting designed to evoke the peculiarly charming and transporting virtues of silent comedy at its peak.

The series is a cooperative enterprise drawing on the inventories of Kino International, which distributes the movies of Charlie Chaplin; Raymond Rohauer, who handles the Buster Keaton and Harry Langdon films, and Time-Life Films, the current custodian of the Harold Lioyd pictures. Ten programs, typically consisting of two features and short, will alternate daily.

Chaplin is represented by six features, three shorts and the three-part compilation; Keaton by seven features and two shorts; Lioyd by six features, and Langdon by the three features that constituted his brief claim to both popularity and artistic importance. Since comedy features in the silent period customarily ran five to seven reels, or about 50 to 70 minutes, the overall running time of the triple bills tends to be a shade over or under three hours.

The silent comedies will be enhanced in many cases by superior 35mm prints - Rohauer prides himself on striking Keaton prints only from the original nitrate negatives, which are in his possession - and in all cases by musical accompaniment, an indispensable element if they are to be experienced as the filmmakers intended and fully appreciated.

The Keaton, Lioyd and Langdon films will be musically supported by Lee Erwin, stationed at the front of the auditorium between a Baldwin electric organ and a Baldwin piano. The live organ accompaniment will be routed through the Key's sound system. Erwin feels that certain moments demand a piano sound and others a combination of organ and piano. Before he died Chaplin supervised the addition of music tracks to his own films. Earlier he had reissued "The Gold Rush" with a score and narration spoken by himself. "City Lights" and "Modern Times" wre, of course, originally released with scores and occasional sound effects.

In addition to providing the appropriate musical moods, Erwin also functions as the resident archivist and fail-safe mechanism. Although a man of calm temperament, he has the will and authority to insist that projectionists show the films in the right aspect ratio. As a matter of fact, he is bringing along the aperture plates necessary to obtain the closet approximation of the vintage 1:33 image ratio, evidently achieved by filing away the parts where a sound track is ordinarily located and installing them in conjunction with a backup CinemaScope lens. Erwin's presence throughout the series should help to insure the enjoyment of paying customers.

After acquiring the Llyod package for $1.5 million a few years ago, Time-Life immediately undercut the investment by inflicting strident musical scores and even more insistent, overexplicit sound effects on the pictures. The vandalism was presumably unintentional and commited with television sales in mind, but it came close to destroying the theatrical integrity of the films. The only thing that saved Lioyd's work from this vulgar gloss was the hair-raising authenticity of the stunt sequences in the vehicles Lloyd called "thrill comedies."

Chaplin had used sound effects discreetly. Moreover, one could be confident that they were the sounds he desired and authorized. Lioyd was posthumously unlucky in his sound and music arrangers, who evidently hadn't paid attention to the admirable support his work received in the splendid compilation movies released before his death, "The Great Chase" and "Harold Lioyd's Wonderful World of Comedy." At any rate, the problem will be solved during "The Silent Clowns" by turing off the Time-Life tracks and letting Lee Erwin rovide the musical coloration for Lloyd's perilous ascents and feverish chases.

The problem might have been avoided all along if the vandals had been given advance copies of Walter Kerr's beautifully written and illustrated critical appreciation, "The Silent Clowns." Originally published by Knopf at the end of 1975, the book was reissued in a large format paperback edition earlier this year.Your enjoyment of the movies is certain to be enriched by Kerr's vivid descriptions of what Chaplin, Keaton, Lioyd and Landon did and his astute analysis of what all that funny behaviour, movement and stylization signified in social, esthetic and philosophic terms.

Among the multitude of the elements and nuances Kerr helps to clarify, hopefully once and for all, are the special comic atmosphere created by the absence of voices or natural sounds and the importance of musical accompaniment.

Kerr points out that "in silent films a performer's hearing was often highly selective. If he could hear at all, he heard what the narrative wanted him to hear." The facts are wittily illustrated with stills from Keaton's magnificent "The General." On the left hand we see Keaton too preoccupied with chopping wood on the tender of his train to notice an entire army passing in the background. On the right hand, we see him hidden under a table, eavesdropping on the plans of Union Army generals that will oblige him to begin the second lap of the flawlessly structured, mirror-image chases that comprise this sublimely conceived and executed epic comedy.

Kerr reminds us that "silent films were constantly assuming that what the audience couldn't hear, the performers needn't . . .Silence was the subtraction that guaranteed films would be, so long as they remained mute, flights of fancy. Flights of a new kind of fancy: fact robbed of its weight and made impertinently, defiantly airborne."

Recalling his own moviegoing childhood, Kerr notes that the "best" theaters maintained full piu-orchestras for evening performances. The less affluent relied on organs, which were also available at the class houses to take over during matinees and musicians' breaks. The most familiar instrumental accompaniment for moveigoers of the '20s was the deep-throated swells of Hammond or Wurlitzer." Moreover, "Music was not an accessory to silent film; it was an integral part of it. The scores on the soundtracks of films today are accessories, very much second fiddlers. They must get out of the way, dive down under, whenever dialogue begins. Silent film music was under no such interdict. It was, in itself, an uninterrupted whole, full partner to the visual image - free, sustained, assertive. To take music from a silent film is to take half its life away."

Kerr believes that while dramatic films certainly lost nothing of their essence and probably gained by the addition of sound, comedy had to change radically. Silent comedy was predicated on contradictions that were undermined by the advent of sound, and only Chaplin was strong enough to resist the change for a while.

"Film was, to begin with, fact, not fancy," Kerr recalls. "That a medium committed to actuality should have embroiled itself in fantasy at all - putting perfectly real objects to such very odd uses - was scarcely to have been expected. That it should have made this fantasy its principal product for something like 26 years is now, even in retrospect, astonishing. For so strange a thing to have happened, film would have had to invent - by hook or crook or happenstance - fantasy of an absolutely unprecedented kind, unrelated to anything the stage had done before it. That is what it did do. It invented a fantasy of fact."

The series at the Key offers the four greatest stars of silent comedy in its prime in a rare comparative showcase. As a rule, the immortal shadows of Chaplin, Keaton and Lioyd tend to impose themselves with little difficulty - the first by virtue of his personality, an extraordinary fusion of sentimental and comic impulses; the second by his astonishing perception of the formal peculiarities of film and his even more astonishing stoic adaptability to a mysterious, overwhelming universe; and the third by his inherent good nature and valiant pluck in the face of obviously authentic danger.

Langdon is the unknown quantity, but it's possible that the format of this series is just what he needs to be reappreciated. According to Kerr, Langdon "existed only in reference to the work of other comedians. He could never have invented the form, as Chaplin virtually did; he was too small, too peripheral for that . . .With the form at hand - a sentence completely spelled out - Langdon could come along and glancing demurely over his shoulder to make sure no one was looking, furtively brush in a comma . . . It is not even enough to know the sentence. We must inhabit it, live in its syntax . . .if we are to grasp - and take delight in - the nuance that was Langdon. You would have to soak yourself in silent film comedy to the point where Lioyd seemed a neighbour again, Chaplin a constant visitor, Keaton so omnipresent that the could be treated as commonplace . . ."

For at least three weeks, just such a retrospective soak will be possible at the Key. CAPTION: Picture 1, Harold Lioyd in "Safety Last": Thrill comdey; Picture 2, Buster Keaton in "The General": Silent fantasy.