OPERA / Ships that collide in the night: Nick Kimberley applauds Jonathan Dove's epistolary romance, Siren Song

Opera, not having much time for psychological development, has long been rather partial to love at first sight: there are coups de foudre in operas as diverse as Cos fan tutte, Carmen and Tristan und Isolde. These days only pop music is guileless enough to believe in love at first sight. Opera, too sophisticated or cynical, must find other emotional crises. Jonathan Dove's Siren Song, premiered last Friday during Almeida Opera, trumps love at first sight with love, sight unseen. Pen-pal romance may seem under-powered for opera, but Nick Dear's libretto, derived from Gordon Honeycombe's novel, provides ample fuel for Dove's eclectic talent.

Before the music begins, we see, projected on a screen, the text of a classified ad: 'Diana, 20, from Southampton, would like to correspond.' The stage- lights go up, a red ring circles the text, a sailor, Dave (Niall Morris), appears. He has ringed the ad and embarks on a correspondence with Diana. Projection is what their relationship is all about.

Ian McDiarmid's production, designed by Julian McGowan, has the stage on two levels. The cast moves between them on a platform; the upper level is the deck of Dave's ship. In a kind of porthole in the sky, lit by a heavenly halo, we see Diana (Tertia Sefton-Green). She and Dave sing their letters to each other. She flirts, feeding his fantasies, some of which appear.

Essentially a shy boy, he eventually declares his love, and the two seal their romance by opening a joint account. They agree to meet when Dave next docks but when he steps ashore he is met, not by Diana but by her brother Jonathan (Omar Ebrahim), who explains that Diana, called away to do some modelling, has sent him and some flowers to say sorry.

Jonathan sets about coaching Dave for his life with Diana - and that's enough of the story. Suffice it to say that Omar Ebrahim at his most devilish makes an utterly reptilian lounge lizard; while Niall Morris's Dave is both cocksure and diffident. As for Diana, Tertia Sefton- Green's ethereal melismas bestow on her a well-judged otherworldliness.

Perhaps spoken performance could have done as much, but it's to the credit of all involved that opera seems the right way. Jonathan Dove has not worried too much about originality. His score is not too proud to learn from Hollywood, from Janacek, from the minimalists. A sinister rattle of percussion, a flourish of harp, a ripple of piano are all placed for maximum dramatic effect, and the orchestra - the Almeida Ensemble conducted by Paul McGrath - supports the singers without overpowering them.

Serving its surprises at precisely measured intervals, Siren Song is at

one moment acerbically ironic, at the next profoundly sympathetic. Its 70-minute duration never feels congested or prolix. A second viewing might encourage doubts, but for me it was love at first sight.

Further performances: 19, 22, 23 July, 8pm. Almeida, London N1 (071-359 4404)