AN EMORMOUS FUZZY MOON hangs over a grape arbor, gilding the elegant curves of Grecian urns and arches, encircling men and women in evening dress with cinematic light. The leaves cast soft shadows over a tuxedoed pianist as he plays dinner music. A pair of "identical" twins wanders confusedly in the garden among those they love and those who love them. This is Illyria, setting of Twelfth Night and one of the prettiest never-never lands Shakespeare ever created, translated with intelligence and sensitivity to a strangely Hollywood-esque Loeb mainstage.

Twelfth Night is updated, relocated and generally reinterpreted more often than most Shakespeare plays. Maybe it's the intricate plot's unique balance of flexibility and limitation that catches the directorial imagination. Mixups in identity, women disguised as men, love triangles, and rowdy servants can be portrayed any number of ways, but identical twins have to look alike, and whether the characters dress in down jackets or loincloths, Malvolio must somehow appear in yellow stockings.

What makes the Loeb show, directed by Sam Samuels, so pleasantly substantial is Samuels's choice of a setting--the lush flesh out the plot and characters with familiar details.

In this context, Feste, the punning, cynical clown becomes Frank Sinatra, leaning on the plano with a drink, entertaining the nobility but keeping his distance. James Goldstein as Orsino, the duke who pines for the love of Olivia (Gaye Williams), is a Casablanca Bogart, white dinner jacket and all. The allusion makes his slow transition to lovesick goon particularly hilarious when he takes to staring soulfully into space, smoking cigarettes from a gold case and obliviously blowing clouds of smoke into the face of Viola (Caroline Isenberg), who, from under her disguise as his servant, gazes just as wistfully at him.

THE FRAMEWORK is clearly apt when so few details need to be tampered with. All the modernizations are properly minimal, though an anachronism or two grates on the nerves--nobody holds bear-baitings in a Hollywood garden. The romantic setting proves its appropriateness most triumphantly in the discovery of a way to get away with Malvolio's yellow stockings (an imaginative coup too tunny to reveal).

Peter Miller's graceful set solves one nagging problem at the mainstage--its enormity. Miller has filled the disproportionate space with arches and arbors and many-tiered platforms. Playing on and around their stuccoed surfaces, the actors, for a welcome change, look at home. Instead of worrying that their gestures are dissipating in the vast emptiness, they just relax and lean on the piano.

A sense of relaxation, in fact, pervades the performance. Most of the comic leads--Feste, Olivia's drunken uncle Toby Belch, (Keith Rogal) his wimpy cohort Andrew Aguecheek, (Peter Howard), and the wench Maria (Dolly Wiggins)--stick to understatement, letting the situations and the lines do the work. This tendency results in several nearly inaudible scenes, like those ones between Sebastian (Jeremy Black) and his follower Antonio--but often it works to the play's advantage, making the occasional broad comedy doubly comic. Rogal as Toby Belch may swallow a line or two, but his grimaces in otherwise underplayed scenes spark hilarity, and one outraged cry of "Madam!" to a thoroughly confused Olivia is the show's funniest moment.

A few characters underplay too far. Isenberg in the role of Viola leaves a bit too much to the script. Hailed by other characters as vivid, brilliant, sensitive, this Viola does little but throw up her hands in despair as she is mistaken for her brother, attacked by Toby and Aguecheek, adored and insulted, and made a pawn of. The play's grand denouement scene falls prey to this gradual slowing of pace, seeming just a bit too serene as a set of twins and two pairs of lovers are reunited.

BUT THE GENERAL EASE pays off by letting every character expand from comic stereotype to reality, exploiting, to the full the scope and potential of Samuels's approach--not to mention the richness of the play itself. An unfunny Malvolio is inconceivable, but the part can easily become unbelievable or grotesque. Christopher Randolph, without sacrificing any comic content, somehow makes his Malvolio heartwrenching as well.

And just as the lyrics in the plays' songs sound more immediate and moving, not less, when set to popular arrangements, every facet of the play takes on more depth and reality as the open space and fresh setting give it room to breathe. Letting the script do the talking, as Samuels does, is probably the best thing anyone can do for a Shakespearean comedy. Furnished with so logical and well-thought-out a setting, it's no surprise that the rest of the play should so serenely follow.