Between Worlds, ENO, Barbican

Composer Tansy Davies and librettist Nick Drake’s opera Between Worlds cannot help but be a devastating tribute to the tragedy of 9/11. Yet the whole is peppered with problems that mean this result is achieved only intermittently. Davies – whose first opera this is – and the playwright Drake, with Deborah Warner directing, have picked a topic that would seem at first glance to demand the scale of a modern-day Götterdämmerung.

This is, essentially, the final section, in which the emotional intensity escalates towards the inevitable. Here the work approaches in earnest the spheres that music alone can evoke, beyond the capabilities of words and even of ideas: the agony of losing loved ones. You would have to have the proverbial stone heart to emerge from the final choral lament without feeling wrung out. The long silence as the chorus filed away in darkness, but for the candles they carried, was a fine tribute to the work, and some members of the audience were visibly devastated.

Nevertheless, Götterdämmerung it is not. As a meditative lament on this human tragedy, Between Worlds succeeds. But as a metaphysical drama of the day itself, there is more to question, and much to clarify.

The action takes place on three levels: at the top, the Shaman is the counter-tenor-as-figure-from-elsewhere (which unfortunately has become a contemporary operatic trope). In the middle are the four nameless protagonists and the Janitor. At the bottom, the chorus, from whom those left behind emerge: a mother, a lover, a sister, a naughty child. Images of New York are projected onto what seems at first a textured backdrop, but consists of myriad sheets of paper, which become variously – depending on Tai Yarden’s video design and Jean Kalman’s excellent lighting – the windows of the World Trade Center, the messages sent home, the building that collapses.

But the four protagonists, each leaving a home situation unresolved as they head to their meeting in the North Tower, are under-developed; we learn little about each of them, or whether they have ever met before. The singers – Clare Presland, Rhian Lois, Willian Morgan and Philip Rhodes – do the best they can with what they have; the young woman is in love with another young woman, the young man is scared of heights, and so forth, but the drama feels undercooked and remains difficult to buy into. The Janitor, strongly characterised and projected by Eric Greene (pictured above in the centre with Lois, Rhodes, Presland and Morgan) is the most powerful figure; it is his task to convince the terrified meeting-goers to call their loved ones to make final declarations of love and regret.

If the Shaman (splendid singing from Andrew Watts nothwithstanding) has a role in these interactions, its significance is not coming across. The programme tells us that he becomes the Janitor’s "spirit guide"– but for those of us not especially conversant with what spirit guides do, this isn’t going to help and the action on stage offers too little clue – perhaps because the split levels allow no actual contact between them. Likewise, if the Janitor’s wife has died, as extraneous information suggests, one could experience the whole evening without realising this from what we see and hear.

The balance seems a bit skewed – at times too naturalistic (“Oh my God”… “What the fuck was that?) and at other times too little so, yet without offering the original poetry the topic seems to ache for, breaking into the Biblical, the liturgical or other languages instead: at heightened moments the Shaman utters some Latin, the Janitor Spanish, the chorus words from the Requiem Mass, the characters psalms. “Out of the deep” – when they are high up in the North Tower? We know it’s meant metaphorically, but still…

In the ghastly reality of 9/11 the place would have been mayhem – there would have been smoke, dust, screaming, flames, desperate temperatures. Yet everything unfolds as if in slow motion, with fluttering papers representing the tumbling South Tower, feeling a tad underwhelming; even the characters ask what that was. The mismatch between too-literal words and over-stylised action leaves a gaping gap that the music cannot quite bridge.

The action gets off to a slow start, which is serious as the whole thing is barely one and a half hours longDavies’s orchestration is atmospheric and the harmonies and textures of the music build tension effectively: high, hypnotic harps, layers of keening strings, the voice-percussion of the Shaman, and bitter, ironic suggestions of telephones are just some of its eerie effects. Many of Davies’s purely instrumental works have a gritty, distinctive, dusky-hued style with a galvanising propulsiveness and fragmented lines functioning in dizzy counterpoint; yet here her high energy feels somehow squished by the strictures of words and voices; the piece might benefit from a greater variety of musical pace.

The structural balance could also benefit from some delicate adjustment. The action gets off to a slow start, which is serious as the whole thing is barely one and a half hours long. Yet the emotional heart of the work arrives when the Young Man’s Mother, gloriously sung by Susan Bickley, offers an outpouring of sorrow in which she declares that there is nothing in this world and time but love; this vital episode is over in what feels like a trice.

Bickley is a marvel in every respect, holding the stage with her sheer presence. Around her there unfolds a terrific team effort: the ENO chorus in magnificent shape, the small orchestra valiant and well balanced by conductor Gerry Cornelius, some haunting aerial choreography by Kim Brandstup and superb vignettes from the secondary characters, notably Sarah Champion as the Younger Woman’s Lover and Edward Green as the Realtor’s naughty child who won’t eat his breakfast (convincingly real kids are in short supply as operatic characters, and this one is terrific).

It would be very, very hard for any work to live up to the demands of this topic. But once you realise the piece isn’t necessarily about 9/11, at heart, but an aspect of the human condition that is intangible, universal and desperately painful to face, you may get past the structural issues, the lack of clarity and the somewhat monochrome pace. Davies at times reaches that place of emotional embodiment that only music can capture, and wraps it in a dark yet cathartic embrace.

• Between Worlds at the Barbican until 25 April