The siege of Atlanta lasted four months. This new musical extravaganza, directed by Trevor Nunn, lasts four hours. Oddly, though, the musical feels longer. I suspect the siege of Atlanta had better jokes, too, and surely better music.

Margaret Mitchell’s squillion-selling American civil-war block-buster, so famously filmed with Vivien Leigh and Clark Gable, has been turned into a show by Dr Margaret Martin, a Californian expert in maternal, child and family health. Which can only prompt the response: don’t give up the day job, honey. Because this Gone with the Wind is one big, windy, flatulent raspberry.

The key to any good musical is the music, and, though Dr Martin studied music theory at the Colburn School of Performing Arts,LA, it doesn’t show. This is depthless pap, boasting every cliché. The live band reaches an identical brassy climax every time Rhett and Scarlett kiss. Or a telegram arrives. Or a child dies. Or at any other point when the audience apparently needs to be told: “This bit’s dramatic, okay, dumb bums?”

Only occasionally are there hints of gospel or good ol’ cotton-field blues. Most of the songs hint at nothing but other bad musicals. When you think what influences Martin might have been open to - when you consider that the same period in the South produced the sublime soundtrack for the film Cold Mountain, with its astonishing sacred-harp songs - it’s an abysmal disappointment.

Then there are the lyrics. These have been “adapted” by Nunn, which only makes you wonder what they must have sounded like before. At one point, I think my ears deceived me. Rhett Butler apparently sang: “The fog was thicker than pasta, just inches from disaster.” Maybe the fog was thicker than plaster, I’m not sure. Either way, you feel embarrassed for all concerned. The reprises don’t help, when the first time was more than enough. Every number bulges with earnest, depressingly aspirational sentiments. People kneel on the ground, gazing heavenward, vowing to be strong: “I will survive. I will go on. I will spread my wings and fly.” That kind of thing. “All men fight for freedom, from the moment of their birth.” Eh? No, they don’t. The emancipated blacks? They sing “Now we are freeeee! Free to live our lives, the way we want to beeeeee!”, or something like that. My ears kept tuning out.

The performers cannot be blamed. They bawl along with genre-appropriate quavering emotion and end-of-line whispers, and always pronounce it “Gone with the Hwind”. An intriguing array of accents suggests everywhere from Bantry Bay to Santa Fe.

Jill Paice is a perfectly credible Scarlett. In other words, you frequently want to slap her. In the movie, she slaps her slaves. That’s cleaned up here, even though portraying racism is not, duh, racist, and its excision only adds to the pervading blandness.

Bestriding this shallow world like a colossus, and the only reason this gets two stars rather than one, is Darius Danesh, commanding and charismatic as that “insufferable peacock” Rhett Butler. Left hand in his pocket, right hand sweeping wide in manly gestures, eyebrows tauntingly cocky, voice like molasses, he perfectly suggests a cavalier (and possibly clap-ridden) Southern gent.

Nunn seems to have directed sleepwalking. John Napier’s design has grandeur, encircling the auditorium with picket fences, trees that, on closer inspection, turn out to be made of stacks of old muskets, and vast flags of Old Glory and Bonnie Blue. Yet it’s curiously static, allowing for no changes, and, after four hours, your eyes are as bored as your ears.

This epic of love and war is reduced to a series of interminable tiffs and tantrums between Rhett and Scarlett, expressed in limp, forgettable songs, the aural equivalent of chewing cotton. Will they, won’t they? Will she recapture him? Will he stay with her? Frankly, I fear, you won’t give a damn.

Watch Trevor Nunn discuss the making of Gone with the Wind at timesonline.co.uk/stage

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