The worst you can say about the Opera House Arts production of “Twelfth Night,” which is playing through next weekend at the Stonington Opera House, is that it is occasionally annoyingly cartoonish and unpleasantly loud. The best is that the show has a vision that is fresh, fun and challenging.

After a successful Maine run with “The Tempest” last summer, Julia Whitworth, who teaches theater in New York, decided to return with a second crackerjack production, this time with a mere sextet of actor-musicians enlisted to play more than a dozen roles in the course of the evening.

On its own, that’s an ambitious undertaking. But it gets better. Whitworth envisions Shakespeare’s setting of Illyria as a swank spa for the rich and rowdy. So when the noblewoman Viola washes up on its shores after a shipwreck, and is joined fatefully by her thought-to-be-drowned twin brother, Sebastian, the circuitous plot zeros in on class distinctions and slippery sexuality.

While Feste the Fool and Maria the Maid, both of whom Whitworth endows with the powers of reason and truth, may not be as blameless or reasoned as she promotes, it’s an interesting take on the us-versus-them thesis, one that Shakespeare explores time and time again, and that Mainers experience every summer with an influx of well-heeled vacationers.

Fortunately, Whitworth is smart enough not to overstretch the idea. Instead, she applies her attention to crisp production values by designers including Ray Neufeld, whose chic and austere white set incorporates a sunken bathtub, a porch swing, cottony banners and a panel of revolving doors. The exquisite detail of dappled lighting by Stephen Brady helps set the mood, and the indie-pop-cum-hootenanny musical score by Daniel T. Denver contributes an emotional immediacy to the characters.

The actors also bring sharp talent to the mix. Melody Bates (Olivia/Sir Andrew Aguecheek) and Shawn Fagan (Feste) are experts in nuance, and they speak Shakespeare with a friendliness and clarity for which every ear should be thankful.

Amy Sevick’s brassiness as Maria wears thin, but she is a formidable stage presence and has the musical equivalent of a green thumb, apparently no matter what the instrument. For most of the night, David C. Wells (Orsino/Sir Toby) vituperates with growling, growing volume, but then turns around and delivers one of the most tender scenes in the show. Clearly, he has a gift for vocal modulation but doesn’t use it nearly enough.

The stylized work of Christopher Logan Healy (Malvolio/Antonio) brings dependability and flair to the piece. And Lizzy Cooper Davis, as both the twins, makes her distinctions with grace and clarity. She changes not one thread of clothing but never leaves you guessing at her identity.

Some may find the double casting confusing. It is. But let’s return to the idea of the best and the worst, not of this show, but of any production of Shakespeare. It’s the worst – not to mention longest – experience in the world if you can’t follow the language or action. It’s the best experience if you can. Obviously, you don’t have to read the script before seeing “Twelfth Night” in Stonington. But it would be better if you do because Whitworth, who apparently is not content to do Shakespeare for Shakespeare’s sake but for the love of intelligent theater, expects a lot from her actors and her audience alike.

In conjunction with “Twelfth Night,” Whitworth and cast members will be holding a two-day workshop, “Tools for Physical Theater: Viewpoints and Composition,” a movement technique developed for actors by theater innovator Ann Bogart, 1-5 p.m. today and Wednesday, Aug. 14. Wells will hold another workshop, “Shakespeare,” 6-10 p.m. Wednesday, Aug. 14. Both events will take place at the Opera House in Stonington.

“Twelfth Night” will be performed 8 p.m. Aug. 16-18 at the Stonington Opera House. For information, call 367-2788.