Production company Unlimited have turned this London staging of Mahogany Opera’s new piece – as part of the Totally Thames festival – into something of an event. There’s a river boat to whisk us over to the lighthouse at Trinity Buoy Wharf for the performance, Icelandic beer, street food, alcoholic popsicles… once we’re there, the trouble is, apart from the long queue for a hamburger, there’s not much to do or see while we wait, quite a long time, for the 45-minute piece itself to start. The wraparound feels like an exercise in indulging corporate sponsorship rather than anything artistically related to the piece.

Things pick up once the show starts. Emily Hall’s new opera-cum-concept album (a concept not without its problems), with words by Sjón (a regular Björk collaborator), is a set of songs that plunge us into the strange situation of a couple whose relationship comes adrift as he becomes obsessed with the electricity pylon outside their house, and she is gradually dragged into his delusions. Along with two singers, accompaniment is provided by harp and keyboard, and a new instrument, the electro-magnetic harp, which produces long, sustained notes to play the role of the pylon itself. The singers are miked throughout, which is slightly alienating in such an intimate performance, but allows for various echoing and delay effects and the blend with the acoustic instruments and Mira Calix’s recorded beats. The songs themselves are beautiful, with lavish melodies and rich, quirky, emotive texts convincingly sung by soprano Sofia Jernberg and tenor Finnur Bjarnason over shimmering and haunting folk-electronic accompaniment.

As a stage performance, it’s very coolly directed, Felix Wake-Walker’s staging (barring a bit of vague and underwhelming gestural work) essentially comprising careful and dynamic placing of the two singers in relation to the space and each other, while Dan Large’s monochrome projections – lines, dashes, light and darkness – flicker and flow across them. All of this elegantly frames each mood and number.

But it feels as though a little too much of the show is still stuck in the ‘concept album’ part of the deal. Hall deliberately created an opera without recitative – it feels unsurprisingly more like a song cycle – and the songs carry us into the centre of each of a sequence of high-feeling moments without much surrounding narrative, or clear momentum through the story. Which is all very well, but somehow unsatisfying, and after the performance, slightly confused, I looked up some of Hall’s intentions, and she has talked about working with psychologists at the Maudsley to research folie à deux (a rare psychotic disorder where one person’s symptoms are transferred to another) and about the narrative surrounding the songs – whole backstories of the characters and specific transformative events in their story and relationship – but the strange thing is that really very little of this essential detail is evident in the piece, either in the music, lyrics, or the stripped-down staging, all of which are undermined by being more concerned with emotional responses to these events that we don’t quite get. And therefore, although working perhaps as an album, as a stage show it feels (and the rigmarole surrounding this performance amplified rather than alleviated this) pretentious, wilfully impenetrable, unnecessarily (if unintentionally) detached: a shame, as there’s something very lovely, and very potent, buried in here.