STORYTELLING is a fickle art. A bad narrator can spin the thinnest yarn into a golden web. If the listener's imagination is to be ensnared, delicate tonalities of setting, suspense and mystery must be orchestrated to perfection. The same can also be said of story theatre.

Developed by Paul Sills (of Chicago Second City fame) at the Yale Drama School, story theatre techniques combine mime and improvisation. Its actors speak not only their own dialogue but also the general narrative line. Props and sets are kept at a minimum, permitting the actors themselves to suggest the imaginative terrain of their work.

So far most story theatre productions have experimented with short, often merely schematic, stories. Broadway's current, warmly received Story Theatre opened with a collection of Grimms' Fairy Tales and is shortly to add a sampling of Ovid's Metamorpheses. A selection of Revolutionary War tales is in preparation. While at the Loeb, Laurence Bergreen, Huck Finn's director, himself staged a handful of Chaucer's Canterbury Tales last semester.

But, dealing with Twain's Huckleberry Finn in the story theatre manner is a much more ambitious project. It's rather like going at a glacier with a pick axe. Not that Twain's story is unmanageable. It's simply that its familiar episodes continually threaten to overwhelm the staging techniques that Bergreen uses to bring the ungraceful narrative to life. Few of his scenes take on an independence of their own and, as a consequence, the audience is left viewing something that looks more like conventional drama than improvisation (and more like high school pageantry than anything else) without experiencing any of the satisfactions that conventional drama offers.

Bergreen has reorganized-and necessarily simplified-Twain in order that Huck's gradual recognition of the nigger Jim's humanity and, more than that, friendship provide a thematic structure. In counterpoint are arranged those episodes ashore in which Huck discovers the prevailing inhumanity of most other pre-Civil War, Mississippi Valley traditions. Perhaps because for many in the audience, suspense is precluded by knowledge of the book, while, for the rest, the bare precis that remains appears emotionally shallow, Huck's journey down the Mississippi lacks even the rudimentary sense of adventure that Tom Sawyer would demand of such an undertaking. And when Bergreen abruptly telescopes the last third of Twain's novel to arrive at a moral and a finis simultaneously, even the impatient are apt to feel more cheated than relieved.

IT'S UNFORTUNATE that the text keeps getting in the way, for there are moments of a quite subtle beauty in this production. Huck's and Jim's self-imposed exile is seen as characteristic of a frontier society in which isolation appears to be the rule. Sara Brownell's lighting and Bob McCoy's piano accompaniment (while the latter seems too often intrusive in the rowdier episodes) are suggestive of the lonely, moral equilibrium that Huck can find only on a raft in mid-river. Fletcher World's Jim, although characterized with an understated dignity and authority that Twain himself hardly could have imagined, delivers a couple of especially effective soliloquys. These are the moments when all the magical elements of the story-teller's art coalesce. But they are numbered.

Generally, the east is not up to transforming two-and-one-half hours of playing time and a windy, winding plot into an evenly exciting experience. In whole episodes they seem to forget about story theatre techniques altogether. In their enthusiasm, cast members often merge narrative with dialogue so that the two are confusedly inseparable. (They could take lessons from Word, who seemed the only one of the troupe to separate the two voices consistently.) True, there are some pleasantly comic moments-mostly in the second act when the "rapscallions" Duke and Dauphin get to pull-off a few of their own put-ons-as well as one or two true comedians in the hardworking company (the actress who plays the hair-lipped Wilkes girl, in particular), but there also is too much undisciplined scuffling and shuffling about even to allow matters to proceed as smoothly as the dream-journey that some critics have suggested Huck's river voyage is. Scott R. Heath adopted notably individualized accents for his bit characters, but not when playing the Duke. Both he and David Keyser, as the Dauphin, were just too relentlessly histrionic and, for all the effort, produced no real characterizations.

Tim Carden, as Huck, had to carry virtually the entire first act himself and the weight of that assignment showed. He has some fine turns, like his mimed escape from Pap's cabin, and he possesses a crazy abandon when it comes to attempting just about any kind of physical stunt. But. in an effort to pace himself for the long haul to the intermission, Carden's voice settled for the unexciting middle road. One just doesn't expect to discover such a subdued Huck Finn.

It's a shame, too. This Huck Finn, while a victim of its own ambition, is always less than the sum of its parts, but you're sure to discover a number of wonderful little things in the production, even if few sustain you throughout the whole performance. And yet Thursday night's audience-many of whom were of high school age-appeared more exhilarated after the intermission than they did at any one point during the show. That too is unfortunate, because story theatre techniques can be incredibly exciting, particularly for mixed audiences of the jaded and the unsophisticated. But, this is one time when the storyteller fails to cast his spell, for the kids Thursday night didn't seem to be taken in by the Loeb's Huck Finn, probably mistaking it as nothing more than animated Cliff's Notes.