The Vienna Volksoper, which began staging opera in 1903, is the Austrian capital's main centre for operetta.

The Vienna Volksoper, which began staging opera in 1903, is the Austrian capital's main centre for operetta. All the more surprising, then, to encounter amid its current repertoire Alexander von Zemlinsky's last opera, Der König Kandaules (1935, but staged much later), and a chilling new staging of Irrelohe (1924) by Franz Schreker, Wagner's most influential successor after Strauss.

Like Schreker's earlier operas ( Der ferne Klang is the best known), Irrelohe is almost overripe. It, too, has a fanciful text by the composer, plus a title that implies "transgression-conflagration", which is what this opera is all about. Set in some unspecified medieval village, it deals with seamy issues: in particular, the survival - think of Pitcairn today - of time-hallowed socio-sexual abuse. Peter (a resplendent performance by baritone Wolfgang Koch), is the bastard son of the local grandee, sired on his visibly scarred mother in an act of rape at her peasant nuptials: a nasty echo of the aristocratic rite of prima nocte.

There's a danger this pattern will repeat itself, for the new Count, Heinrich (the almost as impressive John Uhlenlapp) has fallen for the lumpen Peter's fiancée, Eva (Heidi Brunner). Yet, while evil lurks in every corner in Frank Philipp Schlössmann's impressive yet almost too glowering set, the story yields a kind of happy ending. The fear is that the vocal Heinrich will revisit the sins of his fathers; but Heinrich is a Heldentenor, and they tend to get the bird.

In scenes of Straussian rapture, and with a clutch of steamy love duets, the young couple emerge triumphant. Peter, not Heinrich, has inherited the psychopath gene: in a not wholly satisfactory denouement, it is he who is, almost involuntarily, dispatched by his now redeemed half-brother. Bang on cue, the castle - the old regime - goes up in flames.

The main catch in this often gripping if (aptly) flawed, silly-ideas production by Olivier Tambosi was that the veteran conductor Dietfried Bernet reined nobody in. The entire orchestra played at full pelt, occluding the score's exquisite subtleties.

Peter Rundel made a far better job conducting Hans Neuenfels's bitty but witty production of Der König Kandaules, in which the outstanding performance was that of that Volksoper regular Wicus Slabbert as the complaisant fisherman-usurper Gyges.

'Irrelohe' to 17 December; 'Der König Kandaules' to 14 December (00 43 1 51 444 3670)