A happy ending, with the mermaid marrying the prince and her physical agony conveniently forgotten, is the only major concession that Joel Horwood’s adaptation and Simon Godwin’s staging make to the Disneyfication of Hans Christian Andersen’s tale. The rest is a lively presentation of minor-key material.
    
The mermaid’s father here is not king under the sea, but another oppressed subject of the wicked Sea Witch, who orders all her people to sing up storms so that the kingdom Up There will subside into her domain; the mermaid’s own song calms such a tempest and saves the prince’s life. He vows that he will marry this unknown singer to break the curse on his kingdom (virtually everything, it seems, carries the threat of serious crumbling); but the newly bipedal mermaid cannot tell him the truth as she is now mute, having paid with her voice for the Sea Witch’s magic that gives her legs. The Witch, in turn, plans to use that voice to trick Prince Will (oh, yes) into marrying her…
    
Music is almost entirely live, from mandolin, violin, accordion… and human beatboxing, the cast having been trained in this technique by bmm-tssh maven Shlomo. Katie Moore’s voice as the Mermaid is sweet, but in a slightly nasal contemporary way; Sea Witch Beverly Rudd is more of a belter, and generally gets maximum value out of all her lines, even the high proportion that are “Mwahahaa!” Billy Howle is the epitome of disarming royal gormlessness as Will, and Martin Bassindale and Lindsay Dukes do sterling work as the Witch’s henchcreatures, a crab and an eel respectively. (Poor Bassindale has to make all his entrances and exits a-sidle.) The Mermaid’s undersea movement is directed (by Toby Sedgwick) in a similar way to that of the titular character in The Light Princess at the National Theatre; although Moore’s legs are free but hidden, she is mostly carried by ocean-blue-clad supernumeraries who also flick her finny tail for her.
    
The show has a Kneehighish vibe to it: that blend of yearning and fatalism, scarcely arrested by the upbeat ending. It is a beautifully poignant telling… but, to judge by the polite response on the final preview performance, rather too muted to grab younger viewers. There were few sounds of youthful distraction, but few either of enthusiasm or captivation.

Written for the Financial Times.