Australia’s national treasure plays Cabaret Emcee at his musical homage to Weimar era.

Shabby glamour, brazen jokes with sly, acidic social commentary, cross-dressing in extravagantly bad taste...it’s the stock in trade of Barry Humphries who’s been dealing in it as his alter ego Edna Everage for decades.

But it’s also what you might have found in German cabaret between the wars, during a liberating interlude when the proprieties of buttoned-up Teutonic culture momentarily surrendered to an anything-goes openness.

It ruled the humour, songs and street-art of the Weimar Republic. And those times are of such interest to Humphries that he’s organised a touring musical extravaganza (not his word, but I suspect he’d sanction it) about the Weimar era, opening in London at Cadogan Hall next week.

Why an Australian who lives just off the Finchley Road, where I dropped in on him the other day, should be so ardently Germanophile is odd.

But as he says, “my true address is Heathrow Terminal 5”. And opening the door to me in NW6, he’s wearing one of tho se traditional Bavarian “trachten” jackets. Made for hunting, but high-fashion when you’re not.

“I don’t know where my thing for Austro-German culture comes from”, he confesses, “but I’ve had it since I was at school in Melbourne - where I started a gramophone society at which arty people in turtleneck sweaters would foregather and listen to Kurt Weill.

“It was around then that I bought a stack of early 20th Century German sheet music from a second-hand shop, left there no doubt by a German-Jewish refugee, of whom there were many in Australia.

I knew an old lady in Melbourne who used to say ‘Hitler did two good things for this country: he gave us chocolate and chamber music’. Well, she wasn’t altogether wrong”.

Hitler, of course, was why the liberation of the Weimar years was cut short; branded as “degenerate”, its art burned and its music (which was generally composed by Jews or influenced by black jazz) banned.

“It was a brief window of opportunity”, says Humphries, “looking forward to new places, ideas and experiences.

“The songs are always about going somewhere - usually exotic like Benares or Alabama.

“Ernst Krenek’s once-famous opera “Jonny Spielt Auf” finishes with everybody rushing to the railway station, off to see the new world. As opposed to the old Europe.

“But the music of Weimar was also pre-cataclysmic, on the edge of something dangerous that made it heavy with foreboding and slightly contaminated by the events that would follow.

“That’s where the intensity comes from. It grips you. Well it certainly grips me”.

Humphries was so gripped by Krenek ‘s opera “Jonny” that some years ago he made an effort to direct it at the Sydney Opera House.

“Krenek was still alive in Palm Springs, so I went out there to get his blessing, which he gave me.

“And everything was in progress until Sydney had a last-minute change of mind and decided to do “Pirates of Penzance” instead.”

There will be numbers from “Jonny” at Cadogan Hall, alongside music by Kurt Weill, Ernst Toch, Hans Eisler...and a notorious work by Erwin Schulfhof called “Sonata Erotica” that, when it was published in 1919, was advertised as for “solo mother-trumpet”.

“Mother-trumpet” for these purposes was a soprano who performs a carefully notated fake orgasm.

And at Cadogan Hall, the responsibility for faithful re-enactment of this piece of cultural history will fall to the cabaret artist Meow Meow – who shares the stage with Humphries and the Australian Chamber Orchestra under its director Richard Tognetti.

On all the billings, Humphries’ role is listed as the “conferencier” - which means he’s basically the Emcee: think Joel Grey in “Cabaret”.

And cabaret (the world of Sally Bowles, Christopher Isherwood & co) is more or less the format of the show - though Humphries has some reservations about saying so.

“There are elements of cabaret involved. But you know, that film gives people a false idea of how Weimar cabaret really was.

“My father-in-law Stephen Spender was there with Isherwood in Berlin, and he laughed at “Cabaret” because, he said, the shows they saw during the 1920s were nothing like that. It was all exaggerated”.

So, expect this Humphries show to reference cabaret but not as you’d expect it. He’ll be resisting any opportunity to cross-dress.

“There will be no travesty onstage”, he says, “although of course there may be in the audience”.

As for humour, he insists it will be funny though not necessarily with period-German jokes - despite suggestions that he’s just the man for them.

“I once knew an old SS relic, living comfortably in Salzburg, who said people didn’t realise ‘how much fun we had in the old days’.

“He presented me with a manuscript he’d written called ‘The Humour of the Third Reich’ and wanted to me to find a publisher! Needless to say, I didn’t.

“But his widow told me that just before he died, he sat up in bed and said: ‘That Barry Humphries: the Fuhrer would have adored him’.

“What an endorsement”.

Barry Humphries’ Weimar Cabaret, Cadogan Hall SW1,7.30pm, Jul 29 & 30, Aug 2 & 3. Cadoganhall.com