Not home-grown at the Union, but imported from new production company Triptic, Bernarda Alba is a full-hearted London premiere for Michael John LaChiusa’s ninety-minute musical flamenco version of Lorca’s terrific last play, The House of Bernarda Alba, first seen off-Broadway six years ago.

None of Bernarda’s five daughters is pampered down on the pampas. Materially speaking, they could hardly be vaguer on the vega. Dad’s died, his ashes strewn on the wind, and the show ends with another disaster. In between, the girls champ at the bit, longing for sex, singing with fado-style yelps, and beat off the terrifying contralto incursions of Beverley Klein as their horrid old mother. No doubt Beverley feels Spanish, suddenly Spanish, as she once did in Candide. But mum’s problem goes deeper, and was rooted in her personal life with dad – he treated her like a whore, and now she thinks any woman who looks at a man is defined by the same word. It’s an extreme take on Lorca’s position, but it works, just about, as a spring for the musical.

And Klein is superb, crouched and scheming like a bunch-backed toad, and unleashing her imprisoning conditions with malicious ferocity. The trouble is that she comes and goes a bit, and the play itself (what’s left of it) stutters and dips in the middle, while reasons are found for moving on to the next number.

LaChusia might have made more of the polarity between Klein’s Bernarda and Ellen O'Grady’s wise, more liberal-minded housemaid, Poncia, and you miss the powerful tensions once generated by Glenda Jackson and Joan Plowright in these roles, or even Penelope Wilton and Deborah Findlay at the National six years ago in David Hare’s version.

Instead, Katherine Hare’s strict and well-heated production succeeds best in the ensemble finger-clicking numbers, the claps and the stomps, with Amelia Adams-Pearces’s young Adela clutching her fantasy in a green dress, and Soophia Foroughi’s impressively sculpted Magdalena leading the dance at the harvest, as the men return to work in the fields.

The show is really a one-act opera, and it’s very good to hear un-miked voices, supported by an extremely evocative six-piece band led by Leigh Thompson in a corner behind the audience. The white-bricked house is designed by Hilary Statts, the expressive choreography by Racky Plews of the Gatehouse in Highgate.