The Producers at Sunderland Empire until June 23
A show about a show that is designed to fail has its own in-built excuses, an enmeshed insurance against a mauling from the public and the critics.
"That show was rubbish?" you might say. "But it was meant to be," they will retort.
That is just one of the delicious jokes about Mel Brooks' The Producers, a tale about a failing producer and his rookie accountant who stumble on the realisation that they can make a financial killing from a musical so dreadful that it will close almost as soon as it has opened, leaving them to pocket the money they would have spent on wages.
It began in 1968 as a film and first became a stage show in 2001 (since when, to confuse matters, they have made a film of the show of the film).
The show was a big hit on Broadway and then again in the West End. It has been eagerly awaited in Sunderland where it is in for a long run.
On last night's evidence it will have a happy time on Wearside for this is the kind of predictable hit which would have made producer Max Bialystock and figures man Leo Bloom go pale.
It lives up to expectation, billing and the string of awards it has garnered - and gives us, in Cory English's endearingly devious Bialystock, a central performance of sheer comic class.
The American, sporting bucketloads of brilliantine on a thinning, Charltonesque comb-over, is the very essence of Brooks' New York Jewish anti-hero.
We join him with his star on the wane, his latest musical venture, a show called Funny Boy, having flopped big time.
The creditors are at the gates and then in comes Bloom with his innocently offered great idea. Joe Pasquale is well cast as the fluting Bloom, a man who wouldn't say boo to a goose, but I suspect his co-star could perform with a flock of sheep and wring laughs out of an audience.
What he lacks in moral fibre, Bialystock more than compensates for in charm, as the old ladies who fund his productions in return for sexual favours will testify.
Springtime For Hitler, the worst play ever turned into the worst musical ever, is, of course, as enormous hit - just like The Producers. A "satiric masterpiece," declared one review as the plotters gnash their teeth.
Russ Abbot plays high camp theatre director Roger DeBris and stands in as a suitably incongruous Adolf, surrounded by dancing Nazis with bratwurst on their heads.
The second half show within a show is the highlight, full of the kind of jokes only a Jew could make.
But there are laughs to be had all through, many of them from the sex mad grannies and from the stupendously Aryan Ulla (Emma-Jayne Appleyard) who puts herself at the service of Bialystock and Bloom.
The language is a little strong in places so this probably isn't a show for kids. It might, in any case, confuse their budding awareness of modern history.
For grown-ups it is a wonderful romp, a gloriously silly spiral of jokes within jokes and a thumbed nose to Nazism.