All ladies are like that – especially when they’re at the funfair. Phelim McDermott’s new production of Così fan tutte moves the action to a 1950s fairground setting. The results are gaudy and visually arresting, though not exactly subtle. It's as good a setting as any for this opera, even if the continuous sideshows often threaten to swallow up the narrative, slender as it is. The result is a Così played squarely for laughs, entertaining when it works, but often weighed down by the sheer quantity of interpretive ideas.

From the very start, the staging is presented as a fairground sideshow. As the overture plays out, a circus troupe emerges, one by one, from a trunk, each bearing a placard, which they then arrange and rearrange for comedy effect – the audience’s applause drowning out the music at each punchline. The settings (stage designs by Tom Pye) in the first act evoke a 1950s motel, beginning in the saloon and then moving to the cabins. There’s fun to be had here, with the fronts of the individual rooms rotating to reveal the interiors. Much of the action involves continuous comings and goings through the doors as the sets rotate – proper old-fashioned farce. But as Act I reaches its conclusion, the format begins to feel laboured. One of the final scenes involves just Fiordiligi and Dorabella, but their duets are sung in front of the circus troupe, which gives us sword swallowing, fire eating and the rest of it – in irrelevant distraction. Similarly, most of the second act takes place on fairground rides, with the singers moving from one to the next at each scene change. The teacups are fun, and the tunnel of love is certainly appropriate, but the carousel adds little, and Fiordiligi’s aria floating in a balloon serves no function at all.

On a more positive note, McDermott has some interesting ideas about the characters of Despina and Don Alfonso. Mary Bevan plays a sassy and self-assured Despina, one who takes on all the various disguises with gusto, and who has more agency here than either Mozart or Da Ponte credited her. That impression is consolidated by Bevan’s bold coloratura singing, always accurate and always arresting.

Even better is Roderick Williams as Don Alfonso. He might seem a young choice for the role, but that is all part of the concept. McDermott presents the Don as a shifty spiv, all slick moves and smarm, and more opportunist than philosopher. Williams is fantastic. He is a nimble presence on the stage, and his interactions are just as fluid. And that rich baritone is as warm and satisfying as ever, but agile too and always able to keep the pace.

As for the other leads, the four lovers, they combine well in ensemble, making for a warm and even balance. But, from their arias and duets, it is clear that Christine Rice and Marcus Farnsworth have the edge over Kate Valentine and Randall Bills. The production doesn’t have much more to say about their characters and their schemes, so the dramaturgy here is fairly traditional. All round, a dependable cast, with the only exceptional performance coming from Williams.

Ryan Wigglesworth gives an uncharacteristically relaxed interpretation. His tempi are on the slow side, and he doesn’t put much effort into shaping the orchestra’s phrases. He plays fortepiano continuo under a few of the recitatives, but it's only a token effort. The singers all benefit from the freedom he gives them, but this occasionally tips over into poor ensemble. In some passages, and the Act I finale in particular, the singers and the orchestra got badly out of synch, although Wigglesworth was always able to save the situation eventually.

This Così fan tutte is a high-concept affair and, for the most part, it’s a lot of fun. The fairground setting begins well, but as more and more ideas are piled on, it seems to wander away from the opera’s narrative. It's worth seeing though, especially for Roderick Williams, whose superlative vocal and dramatic performance provides a focal point for this otherwise diffuse production.