At first sight Cimarosa's dramma giocoso seems perfect for a cash-strapped opera company. A six-hander with no chorus, it is cheap to put on. With all the conventions of Mozart but none of the expectations, it has an easy-to-digest veneer. It sits nicely in an auditorium as compact as the Theatre Royal's. Above all, it qualifies as light entertainment - an important consideration for anyone trying to woo an audience.

Maybe that's how the logic ran when Scottish Opera decided to expand its main-stage schedule from four operas to five in the 2008-09 season. But the soufflé that is The Secret Marriage needs a deft cook if plot and music are not to fall flat - which is exactly what happens here. The largest part of the budget has been poured into the set, a split-level domestic interior inspired by the 18th-century architect Robert Adam. It looks handsome, but no amount of dressing up can hide the fact that casting has been done on the cheap. You can't fake Cimarosa's Neapolitan style, with its precise language of musical patter and dramatic pretence: the edifice is too fragile, the dramaturgy too long-winded. This is an opera that needs wit, quicksilver repartee and, above all, experienced players.

This version is little better than a competent student effort. Harry Fehr's staging, designed by Tom Rogers (sets and costumes) and Johanna Town (lighting), updates the action but makes no purchase on the 1950s setting. It is sensibly performed in English - Donald Pippin's translation is good - but comic devices are conspicuous by their absence. The entire show lacks energy.

In this context no one has a chance to shine: even Rebecca Bottone's pert Carolina is less than her usual self. Wendy Dawn Thompson's Fidalma makes a worrying portrait of vocal decline, and it beggars belief that Scottish Opera could not find a better Paolino than the tenor Matthew Garrett. Andrew Slater's Geronimo comes across as a bourgeois boor rather than a figure of fun, while Renate Arends' promising Elisetta is let down by poor diction. Quirijn de Lang's Count fares best of all, and conductor Garry Walker must be congratulated for hurrying things along.

On tour, www.scottishopera.org.uk