By Clare Gabriel BBC News Online

Raunchy, with simulated sex, strong language, even an orgy, Welsh National Opera's latest production pulls no punches in its bang-up-to-date interpretation of a 19th century Viennese operetta.

The WNO opened its autumn season in Cardiff on Saturday with a production of Johann Strauss's Die Fledermaus which set out to shock a traditionally largely conservative audience.

The production pulls no punches

Catalan director Calixto Bieito, who made his UK debut with the WNO in 2000 with Cosi fan tutte, has united with the enfant terrible of British theatre Mark Ravenhill for Die Fledermaus (The Bat).

Ravenhill, of Mother Clap's Molly House and Shopping and F***ing fame, has injected a modern idiom similar to that of Eastenders into an opera whose subject revolves around the hypocrisy of upper-class society.

Bieito, meanwhile, appeals to the whole range of emotions of his audience in a colourful production which moves from trouser-dropping farce in an Austrian tea salon to a Moulin Rouge hedonistic, champagne-swilling pantomime of an aristocratic party.

In fact, you are so overwhelmed by a combination of both Ravenhill's full-on dialogue and the ferocity of the sexual imagery that the music almost becomes second place.

And that is a shame, because some of the principals in Die Fledermaus put in some exceptional performances.

Geraldine McGreevy as Rosalinde and Paul Nilon as her lecherous husband Eisenstein provide the focal point and hold together the many graphic elements around them.

Natalie Christie puts in a fine performance as the chambermaid

Wynne Evans plays Rosalinde's lover Alfred with some good Welsh humour. Their drinking and amorous antics are a highlight of a the first act.

Natalie Christie as the chambermaid Adele is also captivating, and her performance as a would-be actress in Prince Orlofsky's party is another highlight of the second.

Somewhere along the way though the production seems to lose a sense of clarity about its own identity.

But this is perhaps what Bieito is seeking in his portrayal of a society whose morals have little relevance to Wales or Britain in 2002.

And in trying to refocus the operetta into a modern context, perhaps the purpose of the exercise becomes unclear.

Vienna, as elsewhere in Strauss's time, was an outwardly moral society which masked a hard core of sexual licentiousness.

In the confusion of the second and third acts where high-class party and prison cells are merged, you get more than a sense of the immorality which ruled the day.

However, the endless round of trouser-dropping and pretend sex has the final effect of making you feel you are watching a good old British pantomime mixed with a strong dash of farcical elements.

Welsh National Opera's Die Fledermaus plays until November 15 at theatres in Cardiff, Bristol, Liverpool, Birmingham, Oxford, Belfast, Southampton and Swansea.