Seven Oregon farm boys blow into town and help themselves to seven sisters in this thoroughly likeable, totally un-PC hoe-down re-write of Plutarch's Rape of the Sabine Women. The Sabines are sobbin' and the Romans are Mormons. Welcome to the backwoods and beyond.

The 1978 stage show based on Stanley Donen's 1954 MGM movie, never a Broadway or West End success, was always a galumphing hybrid, but Rachel Kavanaugh's revival, with some stunning, balletic choreography by Alistair David, proves mostly irresistible, though never a classic.

Mythic, more like, if you want to view the main girl Milly's taming of the crew of Biblically named, hirsute hillbillies as an education in civilising sex manners, just as, in brutal reverse, Petruchio's "enslavement" of Katherina can be seen (as Jonathan Miller argued) as a dramatised handbook of an ideal Elizabethan marriage.

Alex Gaumond as Adam launches the indiscriminate babe hunt from the top of the auditorium: "Bless your beautiful hide, wherever you may be; we ain't met yet but I'm a'willin' to bet, you're the gal for me…" Hairy and uncouth, Gaumond's too damned nice to dislike, and he's soon charming the lips off his prey, Laura Pitt-Pulford's Milly.

Then begins the etiquette regime when Milly discovers Adam's six bro's in their bad wigs and smelly long johns. She don't mind cooking, but there's no muffins or flapjacks for this lot till their jimjams are in the wash. Then, back in town, at the harvest social, the spruced up lads, suddenly transformed into a bunch of supple-toned, thigh-rippling pirates in Le Corsaire, take over the barn dance.

This sequence doesn't match (how could it) the Michael Kidd choreography in the movie, and the incomplete barn remains that way. But there's a spectacular, plastic mobility of axe-jumping, cartwheeling, trestle table-assembling, polka prancing, plank bashing and fist fighting.

Kavanaugh's production is good at suggesting the consensual mutuality in the subsequent abduction. The lads may turn up with ropes, bear-traps and blankets, but the gals are excited by the "back to nature" farm boys, bored with the stuffed suits in the pioneer town twelve miles away. The seasons pay their part, too, snow-bound, lovelorn lads clutching cushions to their groins (huh?) and Adam taking to the hills with a bottle while Milly is in labour.

The original movie songs have a breezy melodiousness in Gene de Paul's music and wit and literacy in the maestro Johnny Mercer's lyrics; the five added 1978 songs by Al Kasha and Joel Hirschhorn simply don't. They vary only in degrees of sententiousness, drabness and mediocrity, and stick out like sore thumbs in the charm and naivety of the rest of the show.

Good work as ever, though, by musical supervisor and dance music arranger Gareth Valentine, musical director Stephen Ridley and designer Peter McKintosh who manages to convey both town and remote farm by dressing two giant flat pack wooden structures on a broad open stage backed with elegant tree trunks to complement the natural setting.

The youngest of the seven brothers (Russ Tamblyn in the movie) is beautifully done by whey-faced Sam O'Rourke, neatly partnered by Bethany Huckle's dimpled, curly-headed Alice. And when the boys aren't stomping all over the stage in their boots and neckerchiefs, the girls are swirling around gracefully between them in a blur of pastel-coloured checked gingham dresses and simpering giggles.

Just when you're worrying about women knowing their place in support of a man, and so on, they all burst into concerted joyfulness in the best musical item of all, "Spring, spring, spring." And you have no choice but to give in, roll over, and look forward to the summer.

Seven Brides for Seven Brothers runs at the Open Air Theatre, Regent's Park until 29 August. Click here for more information and to book tickets.