STRATFORD, Conn.--Let me confess at once that, of all plays in world literature, Macbeth is the one that enthralls me most. I do not claim it is the greatest play--or even Shakespeare's greatest play. After all, the only source is the posthumous First Folio edition, which presents difficult textual problems and is several stages removed from the dramatist's original script. On the one hand, it certainly contains some passages that were foreign interpolations; on the other, it possibly lacks one or two scenes that the Bard originally included. As it stands, it is only about half the length of Hamlet; and The Comedy of Errors is the only shorter work in the canon.

Despite the imperfect state in which the play has come to us, Macbeth surmounts all obstacles and has the power to grip you like no other. I don't mean just its ability to engage the mind; the play has an almost corporeal existence, and can seize you by the throat and wring you out.

One example of the work's appeal came in May of 1849, when on the same evening in New York City there were three simultaneous productions, starring three eminent Macbeths of the time--William Charles Macready, Thomas Hamblin, and Edwin Forrest. These performances led to what has become known as the Astor Place Riot--the worst fracas in theatrical history, besides which even the celebrated free-for-all in Paris at the premiere of Stravinsky's Rite of Spring seems pale. At the final tally in New York, 31 persons were killed and more than 150 injured. Such is the incredible power of Macbeth. Even in an age with less belief in witches than obtained in the Jacobean era, perhaps we must ascribe some of the work's power to the very supernatural that this play invokes to a larger extent than does any other in Shakespeare's output.

And now for the third time the American Shakespeare Theatre has essayed this masterwork. In 1961 Pat Hingle was woefully miscast in the title role. Six years ago John Colicos was an impressive Macbeth, but poorly supported. For me the current go-around, staged by the AST's artistic director, Michael Kahn, proved frustrating.

THE NEW production is fascinating in concept. It is engrossing to look at, both in its shifting settings and in much of its bits of business. But while it intrigues the eye, it assaults the ear. What a shame that all the effort that went into the technical aspects is so severely scotched by the vocal ineptness of its main players!

For a drama so intentionally full of ambiguities, unusual latitude is afforded a director. Although the historical events on which the work is based lay in the 11th century, Kahn has quite legitimately placed his characters in the time of James I. In choosing a tale from Scottish history, Shakespeare was paying tribute to King James, himself a Scotsman; and in giving such a major role to the supernatural, he was honoring not only a king deeply interested in witch-craft but one who had himself recently written a treatise entitled Daemonologie.

Kahn has further conceived the three witches--or "weird sisters," as they are repeatedly called--as not only having their own spooky lairs, but also as permeating regular society. Thus they are garbed as wives of members of the court, and are listed as Lady Angus, Lady Caithness, and an unspecified dowager. They often hover on the sidelines, and even take over the small role assigned to Lady Macbeth's servant. It is only in their incantatory privacy that they become obviously witchlike by donning half-masks. (Kahn of course omits the spurious interpolations involving Hecate, the patroness of witches; less commendably, he had done a little further cutting, though the production has a running-time of only two and a third hours.)

But if Kahn emphasizes the ubiquity of the clairvoyant witches, he has also underlined the Christian milieu in which his characters live. In fact he had framed his production with a mimed prologue and epilogue, both laid in church. Accompanied by the ringing of bells and the chanting of plainsong, the show opens with King Duncan receiving communion and ends with his son Malcolm being crowned. The officiating priest, crosier in hand, also functions as the Old Man who talks with Ross, and later as the Messenger who urges Lady Macduff to flee with her children.

Furthermore, the characters frequently cross themselves. And much is made of a crucifix from time to time; even one of the witches wears a pectoral cross. When Macbeth sits on his ill-gained throne and exclaims, "To be thus is nothing," he rips the cross from his chest and throws it to the floor, whence, in a neatly ironic touch, it is shortly picked up and handed back to him by the First Murderer.

THE costumes, by Jane Green-wood, are prevailingly black, with white or gray trimming. The exceptions are good King Duncan, who wears the white of purity, and, similarly, Malcolm at his eventual coronation. After the murder of Duncan, Macbeth and his wife, in their hypocritically assumed purity, are the next appearance of white, to be followed by their blood-red robes in the daytime.

The raked stage is dominated by a pair of 20-foot-high steel panels, each with a portal that can be open or shut. The insides of the panels are serrated, so they can close together as tightly as the vise of Destiny grips its victims. Sets of steel stairs roll in and out. When the panels are separated, we see in back a drop with a huge translucent circular screen, on which mobile projections are thrown from the rear.

The settings, fashioned by Douglas Schmidt, and skilfully lit by Marc Weiss, are decidedly modern or futuristic. And electronic incidental music and odd sound effects have been devised by Pril Smiley. One might surmise that the result would be a mishmash. But the idea of putting 11th-century people dressed in 17th-century garb in 20th-century environments is perfectly viable. One of the play's major themes is the wrenching of things out of their accustomed habitats, the appearance of people in "borrowed robes," the distortion of time. And the text is full of references to strange sounds ("every noise appals," Macbeth complains).

There is a fusing of the steel of modern architecture with the armor of medieval soldiers. Even the terrible knocking at the gate is not the usual pounding on wood but instead a clanking on metal. This is a cool, gray world. The huge portraits of Duncan and later of Macbeth and his wife, which are dropped down from the grid, are not colored oils; they are stark black-and-white photographs. Touches of color in this production are rare, and thus all the more striking.

When the witches await Macbeth's first visit, the circular screen shows a sort of magnified and pulsating green organism. At "A drum! A drum! Macbeth doth come," we hear--indeed we feel--the pounding of heartbeats; but the heart, significantly, is afflicted with arrhythmia. In the scene where Ross calls attention to the solar eclipse, the circle becomes a view of the period of totality with its brightly flaming corona. When Banquo is murdered and Fleance escapes, the circle becomes a blood-red target with a bull's-eye of blue, the color of heavenly innocence.

Especially effective is Macbeth's last encounter with the witches. A green-lit trap in the stage is the cauldron in which they make their unholy brew. Simultaneously the vertical circle functions as a top view of the cauldron, changing colors constantly like a kaleidoscope. When "a baboon's blood" is added and Macbeth drinks of the brew--a fine idea--the circle turns red. Then superimposed come the three apparitions, followed by the series of eight kings as a pinwheel. It's a show of virtuosity, but it works.