I was already imagining it. A Holocaust musical. A musical — about the Holocaust. How was that going to work, then?

“The weather’s a stinker,

We’re bound for Treblinka,
But in only a blink of an eye,
We’ll be flying in the sky,
You and me-e-e-e!
Our spirits soa-oaring
Forever free!”

Imagine This is an original story by Glenn Berenbeim, who has previously written a US television series called Touched by an Angel. Unacquainted with his work, I did some quick research, only to find that one viewer of the programme said he found it so sickly that he “afterwards spent three hours vomiting stomach acid into a bucket”. The music is by Shuki Levy, who has previously written tunes for He-Man and the Masters of the Universe, and the blurb promises: “An inspirational story . . . a story of hope; where laughter rises above the tears; where freedom is found through imagination; where love knows no boundaries.”

So far, so worrying. So what is the story, exactly?

With some relief, you find that it’s not exactly a musical about the Holocaust. It’s about the Warsaw-ghetto uprising in 1943, an unbelievably heroic episode of civilian armed resistance against the Nazis, with the shadow of the Holocaust hanging darkly in the background. In fact, Imagine This barely touches on the armed uprising, either. Amid all the mayhem, brutality and death, it focuses on a small group of Jewish men, women and children, mostly of the Warshowsky family, who are rehearsing a stage play about Masada. Echoes of Les Enfants du paradis, perhaps — and although in no way comparable to Carné’s masterpiece, the idea behind Imagine This is already beginning to look a little more respectable.

As rumours of the Final Solution gather strength, the troupe of actors and singers have to decide how to stage The Fall of Masada, and what its significance is.

Masada, if you don’t know, is a stunning natural fortress plateau in the Judaean wilderness, where a band of 936 Jewish zealots held out against the Romans in AD73, then committed mass suicide rather than face enslavement. In fact, the story would make an excellent movie for Mel Gibson, if it weren’t so full of Jews.

The two stories, Warsaw and Masada, intertwine and echo each other, with parallels sometimes stretched to breaking point. The biggest problem, however, is that the 20th-century Polish-Jewish family and their struggle to survive are far more immediate and engaging than the stilted costume drama of Masada, with its huge Roman eagle that looks more like a guinea pig with wings.

“Old, unhappy, far-off things, and battles long ago.” Too long ago.

Back in Poland, the head of the Warshowsky family is Daniel, the moral heart of the piece. Beautifully played by Peter Polycarpou, he is full of bitter little jokes and courageous sarcasm in the face of the SS bullies and sadists. “Something about the Third Reich doesn’t agree with our health,” he explains. And, trying to encourage them to come along to the play about Masada, he assures them: “You Nazis will love it. It’s got singing, dancing, and all the Jews die at the end.”

Also notable is Leila Benn Harris as Daniel’s daughter Rebecca, and the youngish cast sing with talent and passion. Eugene Lee’s set manages to be both dingy and dramatic, and the lyrics sometimes rise to a certain ominous poetry, in view of what is to come at Treblinka: “Imagine you decide what’s true, And see a sky of ash turn blue.” At other times, however, they have just the kind of banality you dread in such a context. “We will run, we will flee, and somehow we’ll be free-ee-ee!” the young lovers sing towards the end, as they magically escape from the ghetto to a wonderful new life — doubtless in America. Levy’s score treads a middle course of dull predictability, with never even a hint of Yiddish or klezmer music. What a waste.

And, of course, there are plenty of holes to pick in the history. Imagine This accepts without question the myth of Masada as a heroic last stand by the Jewish people against a prototype-Nazi Roman army, which simply doesn’t bear examination — though there’s no doubting the centrality of the myth to modern Israel. (To this day, after they have completed basic training, Israeli soldiers are sworn in by torchlit ceremony up there, swearing the oath “Masada shall not fall again”.) The players sing praises to Masada’s “beauty and endless bounty”, which is unconvincing too. I’ve been up on Masada, and beauty and bounty don’t readily spring to mind. It’s more like being stuck under a hairdryer for eight hours.

In AD73, we are told: “The Jewish people were marked for destruction.” No, they weren’t. The Romans just wanted to stamp out their rebellion. Many of the zealots on Masada had already been thrown out of Jerusalem as trouble-makers — by their fellow Jews. The parallels with Warsaw 1943 start to look ever more creaky, and not for the first time you feel the hopeless incompatibility of the colourful song’n’dance musical with the grey shades of history. There are exceptions, of course — from Cabaret to Les Mis — but Imagine This is no Cabaret. Full of crude, if strong, emotions, but essentially simple-minded, it leaves you with the feeling that, fun though it is, it’s not really suitable for grown-ups.

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