Opera: Sarka/Osud, Garsington House, Oxford

Double helping of rare Janacek

At Garsington Opera, it isn't just the directors, designers and performers who must make that blind leap of faith into the realms of fantasy. The audience, too, must use their imagination. Here we are perched somewhat incongruously upon a makeshift auditorium in the chairman's backyard. There are trees beyond the out-buildings but there are also backcloths of painted trees.

At Garsington Opera, it isn't just the directors, designers and performers who must make that blind leap of faith into the realms of fantasy. The audience, too, must use their imagination. Here we are perched somewhat incongruously upon a makeshift auditorium in the chairman's backyard. There are trees beyond the out-buildings but there are also backcloths of painted trees.

Indeed, the distinction between what is real and imagined is so blurred we might conclude that the eccentrically dressed gentleman approaching through the flower beds of the Italian garden is a latecomer hot-foot from the champagne bar, not a mythic Czech warrior hot-foot to Vysehrad. We might even conclude the grey buildings before us are part of the castle. The birdsong (real) swells with the ensembles, lending atmosphere to the woods (imagined) beyond the castle. And we haven't yet taken account of the weather.

This season's Garsington coup is the British professional stage premiere of Janacek's first opera, Sarka, in a double-bill with our first staging, in Czech, of his extraordinary and much later Osud. The reasons for the neglect of both are largely technical. Present them in tandem, as here, and you are talking, realistically, of two sets of principals and, in the case of the latter, a big cast including a troupe of young girls. Dramatically, Sarka is a complete non-starter, being largely focused on an armed revolt of Amazonian women against the patriarchy. Not even the director Olivia Fuchs could advance the cause of feminine supremacy with this one. But it was good to hear in the flesh, not least to have confirmed again how all the distinctive elements that make up Janacek's operatic language – the dramatic and emotional shorthand, the concentration of time – were in place from the start. So, too, his deep and abiding lyricism, enriched here with a strong vein of patriotism worthy of Smetana.

Garsington even found a Czech tenor, Ludovit Ludha, as the white knight Ctirad, and had Susan Stacey give us plenty of Amazonian welly as Sarka. But Garsington is hard on voices. The same with the industrious but horribly exposed orchestra under Elgar Howarth. The covered but essentially "open air" environment offers no refuge, no acoustical bloom.

Adrian Thompson as Zivny, the composer – Janacek's alter ego in the art-imitating-life-imitating-art world of Osud – would certainly have benefited from a more grateful acoustic. The voice can sound lovely in repose but brays unforgivingly under pressure. And there's a lot of pressure in Osud – not least in the great "flashback scena" of the final act. The highly filmic aspects of the narrative were cleverly contrived by Olivia Fuchs. The busily eventful opening scene was expertly blocked, Janacek's intoxicating carousel-like waltz bringing an entire spa town out to greet the sun. Here's where the weather played its part, a torrential downpour lending a touch of surrealism to the tennis whites and sun umbrellas. Again, we were called upon to use our imagination as the troupe of young schoolgirls skipped their way through the Italian garden. Sunkissed not soaked, we kept repeating.

Otherwise, the astonishing originality of the score certainly registered, though the venue and the coarseness of some of the singing put paid to much in the way of light and shade. I wasn't sure about the Mrs Bates-like knife-attack on Mila by her demented Mother. Doesn't that turn "accidental" into "intent". And Zivny's exploding piano? "A bolt from the blue"? Nature had already seen to that.

To 13 July (01865 361636)