Le nozze di Figaro is an Italian opera, composed by a German and adapted from a French play, all of which make it easy to forget the work’s original Spanish setting. But the elaborate Moorish sets for Michael Grandage’s new Glyndebourne production put Spain firmly to the fore, casting aside the 18th century in favour of lusty goings-on in a 1960s country villa, somewhere outside Seville.

Transposing the action of Figaro to Franco’s Spain is not a new idea. Ian Judge’s 2004 treatment for LA Opera also explored this period, identifying the natural parallels between the social and political tensions of the dictator’s boom years and those leading up to the French Revolution. With change just beyond the neatly-trimmed hedges bordering the Almaviva estate, wealth and excess celebrate an uneasy victory in the outmoded rites of the privileged classes.

As the Overture struts to a poised close and Count and Countess pull up in their open-top sports car (a scene-stealing antidote to the many animals on the opera stage in London recently) it becomes clear that music and drama aren’t entirely in sympathy here. While Robin Ticciati and the Orchestra of the Age of Enlightenment offer a determinedly understated reading (the climaxes of the Overture are rarely outdone by the pianissimos), Christopher Oram’s sets are a constant forte in their excess – all Alhambra arches and intricate mosaic tiles. Both however manage to drown out the dramatic intrigue on stage.

Grandage seems determined to reject the sitcom-style operatic comedy currently in vogue, opting instead for a delicate naturalism whose gestures seem barely to reach beyond the orchestra pit. The resulting comedy is hard-won (blunted often by brutally truncated and inexact subtitles), never quite achieving the flow that Mozart’s score demands, and having knock-on impact for some too-heavy recitatives. It’s no disaster, but given this cast, conductor and visual context we could so easily have had so much more.

Characterisation succeeds best in the smaller roles, investing Isabel Leonard’s gorgeously-sung Cherubino with gangling awkwardness, and transforming Don Basilio (Alan Oke) into a prancing poseur. The romance between Andrew Shore’s Bartolo (the dramatic high-point of the evening) and Ann Murray’s Marcellina is also a delight.

Despite the riotous décor and the screaming Pucci-print of her own outfits, Sally Matthews’s Countess achieves the sudden stillness the role requires, shocking us out of the glossy strife of Susanna and Figaro with both “Porgi amor” and “Dove sono” and into the altogether more terminal convulsions of her marriage.

Thanks to the some rather under-projected performances from Vito Priante’s Figaro and Audun Iversen as the Count (the latter all but benign, so smiling is his seduction), greater than usual emphasis falls upon the scheming women – weight that both Matthews and Lydia Teuscher (Susanna) manage to bear. Teuscher’s neat vocal delivery is at its best in the first two acts, relishing the playful intrigue but never quite following through with the darker emotions of Act Four.

There’s a ferocity, a feral energy to Figaro that kicks against the bourgeois conventions of its setting. Here, in the grounds of an English country house, Mozart’s own estate struggles to locate this, settling too easily instead into a gentle drawing-room farce. Having set up a historical context of such resonance and specificity, Grandage fails to follow through and engage with it, leaving his characters unmoored and floating somewhere between their eighteenth century originals and his liberated sixties incarnations.

Le nozze di Figaro is an opera with a special history for Glyndebourne – having opened the festival back in 1934 and received some 500 performances in the intervening years. With 12 years since Graham Vick’s production, all eyes (and ears) were on Grandage and Ticciati to deliver a reading for a new generation. While theirs could still be the production we’ve been waiting for, as yet it isn’t quite.

Michael Grandage's production of Mozart's Le nozze di Figaro will run at the Glyndebourne Festival until Wednesday 22 August 2012.