Like Nikolaus Harnoncourt, René Jacobs et al before him, the Greek-born, Russian-domiciled conductor Teodor Currentzis positions himself as a Mozartian agent provocateur, bent on roughing things up. If you read the long booklet interview, by turns illuminating and pretentious, you’ll have a fair idea of what to expect. From the frantic Overture, conducted as if on hot coals, this is a <i>Così</i> of violent extremes. Tempi tend to be either breathlessly fast or – say, in the girls’ initial duet – languorously slow. Dynamic contrasts are played up for all their worth, and beyond, with the Perm orchestra consistently favoured in the balance. Accents detonate like nuclear missiles. Recitatives hurtle precipitately into arias and ensembles. The continuo group is reinforced by lute and demotic hurdy-gurdy, while the facetious keyboard chuckles and flourishes make Jacobs’s fortepiano seem a model of self-denial. </p>

<p>If <i>Così</i> is, along with Verdi’s <i>Falstaff</i>, the ensemble opera par excellence, the casting of Fiordiligi, especially, is crucial. With her slender, agile soprano, deployed with minimal vibrato, Simone Kermes makes Fiordiligi unusually vulnerable and introverted. Both in aria and ensemble she often deploys a frail, slightly breathy tone, à la Bartoli, as if testing the limits of softness. It’s a performance of subtle intelligence, though as with her Countess in Currentzis’s <i>Figaro</i> (3/14), I sometimes craved a fuller, warmer timbre. </p>

<p>With a similarly light, almost ‘instrumental’ timbre, Malena Ernman characterises the flighty Dorabella with zest and blends well with Kermes in their mellifluous chains of thirds. Except in a rather bland ‘Un’ aura amorosa’ (where Currentzis’s soporific beat does him no favours), Kenneth Tarver makes an ardent and elegant Ferrando, while until his moment of betrayal the mellow-toned Christopher Maltman is all blithe, jack-the-lad insouciance as Guglielmo. The conspirators make their mark, too, especially Anna Kasyan’s brightly sung, slyly timed Despina, though I wish she’d been less lavish with the cackling laughter. </p>

<p>If Currentzis can push the lusty period band to the edge of the possible, instrumental colours are startlingly vivid. Rarely are so you aware of Mozart’s novel use of trumpets as surrogate horns, a brittle foil to the sensuous <i>tinta</i> of clarinets and bassoons. Several scenes have a thrilling manic energy. Yet for all the colour and theatricality, I found it hard to rid myself of the feeling that Currentzis is striving too self-consciously for effect. There’s an intermittent charismatic brilliance here. But for a <i>Così</i> in similar mould, yet admitting of more grace and wit, I suspect that René Jacobs is likely to wear better on repeated hearings.