In 1742, Handel's opera Imeneo was a huge hit in Dublin. Now, after 250 years of neglect, it is being revived at the Gaiety, reports Arminta Wallace

Sometimes a photograph really is worth a thousand words. Picture this, for example. Three figures are seated on a park bench, backs to the camera: two short-haired heads and one with hair pinned into untidy pigtails; from left to right, boy, boy, girl. The boy in the middle has his arm around the girl's shoulders. A couple, then? Look again. Behind the bench - behind the scenes, as far as the people in the photograph are concerned, though very much in the foreground from the point of view of anyone observing the photograph itself - the girl and the other boy are holding hands.

And there you have it: the plot of Handel's opera, Imeneo.

Baroque operas are usually tangled tales which feature a couple of mis-matched pairs and a fistful of assorted misdemeanours and misunderstandings. But not this one, where girl must choose between two boys, end of story.

"I came across the image on a postcard in Freiburg, where I was working," explains the director of Opera Ireland's forthcoming production of the piece, David Bolger. "And I went 'wow, look at that! That's Imeneo!' "

The reaction of Irish opera-goers is likely to be more along the lines of: Handel's opera, um, Imen . . . eh? Although we have a solid tradition of Handel opera productions and have seen a reasonable number of them on stages in this country over the past 15 years, few people are likely to have heard of Imeneo, which was last performed here in 1742 and hasn't received many performances anywhere in the interim. Who decided to stage it in 2005?

"It was my idea," says Opera Ireland's artistic director, Dieter Kaegi. "A friend of mine is preparing a new edition of the piece with a music publisher, so we acquired the rights - and now we have the first performance for over 250 years."

At its 18th-century London premiere, two years before its Dublin outing, Imeneo was a famous flop. However, even the briefest acquaintance with the music reveals a sparkling score packed with delightful arias. By the middle of the 18th century Handel had been turning out Italian operas for more than 40 years and was an expert in all aspects of the form - so what was the problem?

"It's hard to say," says Kaegi. "It could have been the cast, or the humour of the audience on that particular night, anything really. If you look at pieces which are popular or not popular today, it's very hard to understand why one has failed while another is successful. There's no hard and fast rule about it."

In truth, many of today's most popular operas - including Verdi's La Traviata, which is also being staged by Opera Ireland at the Gaiety Theatre this season - made disastrous debuts, only to go on to later fame and fortune.

Undismayed by the fate of Imeneo, the wily Handel gave the score a major overhaul, rearranged the voices, added extra choruses and staged it at Fishamble Street in Dublin - where it was a huge success.

"It's not a question of a slight change here and there," says Kaegi. "Essentially, it's a whole new opera. There were two performances here, but we don't know very much about them. We don't even know if it was staged or semi-staged."

Opera Ireland's new production will, in a way, be double-staged. Bolger plans to open the action with the cast performing as if they were themselves rehearsing a show, bringing the audience into two parallel worlds. Gradually, the piece will develop into a full-scale baroque opera, with scenery and costumes to match.

The artistic director of CoisCéim Dance Theatre Company, whose first venture into opera direction with Opera Ireland last year produced the award- winning Orfeo, Bolger says he has found 18th-century opera seria to be seriously addictive.

"Somebody said to me that in recent times a lot of choreographers have been directing baroque operas, which is interesting. I didn't know that," he says. "I trained in classical dance, so obviously music is a big influence in my work anyhow, but after doing Orfeo last year, I did get kind of hooked. I find it fascinating that this piece was written in 1742, and is still around - and still has something new to say to audiences."

Still, when he first listened to recordings of Imeneo, he says he felt quite intimidated by the music. Why?

"I just get scared," he says. "You hear this orchestra going, and then somebody sings, and I think 'uh-oh, I don't come from that world'."

But then, while working on a dance show in Freiburg, he came across the image described above, of the three people sitting on a park bench.

"I saw the postcard and I went 'okay, now I know how to do this'," says Bolger. "Then I saw a still from a film. I don't even remember what film it was, but it was two people kissing. Or at least, one guy was hugging a girl and she was kissing somebody else, over her shoulder. And I thought: 'This is exactly what Rosmene's in the middle of in this opera. She's being torn in two.' "

To be precise, she is in a love triangle with Tirinto, to whom she is engaged, and Imeneo, who, having rescued her from pirates, demands that she marry him to demonstrate her gratitude. Such outré shenanigans are not unusual in Handel operas: Serse features a king earnestly singing an ode to a plane tree, while in the opening act of Rinaldo, the hero's wife is carried off by a black cloud. What is unusual about Imeneo, however, is that it reverses the accepted order of things in the male voice department. Most of Handel's Italian operas were vehicles for the superstars of the day, the castrati, who commanded massive fees and attracted packed houses.

In this case, however, while the castrato role of Tirinto carries by far the most musical clout, it's the baritone, Imeneo, who gets the girl. Castrati being in short supply nowadays, the role of Tirinto in Opera Ireland's production will be sung by the mezzo-soprano, Wilke te Brummelstroete. Which, says Bolger, will allow the production to give a knowing nod to the gender-bending situations which this kind of opera takes for granted.

"I think Handel wrote the opera this way in order to surprise his own audiences, in a way - because the musical star doesn't get the girl," he says. "It was to keep them guessing. Not that it's a big surprise ending or anything. I mean, the opera is called Imeneo, not 'Tirinto', which is a bit of a giveaway."

Dieter Kaegi, for his part, reckons that plots weren't a big deal as far as Handel was concerned. He's in a good position to give a verdict: a fan of many years' standing, he has recordings of all the available Handel operas.

"The plot of Imeneo is not, I would have to say, one of Handel's best - and he probably didn't care that much," Kaegi says. "Except for Alcina and Julius Caesar, the stories are not the biggest thing in Handel operas."

But Kaegi insists that, as an opera composer, Handel was way ahead of his time.

"Especially in this opera," he says. "You would think that it was something that was written 100 years later. He was really a forward-looking, forward- thinking composer. It's there in the structure of the music, in his courage in composing new patterns, things that sound completely wrong for the period, just as you hear things in Bach sometimes and ask yourself: 'How would a composer of that time dare to write this?'

"Handel was a huge success as an opera composer in his own time - and he is just as popular now. And one reason, I think, why people find Handel's operas so appealing is that if you look at contemporary music - especially the minimalist music of Philip Glass or John Adams - the patterns of the music are very, very similar. You get the endless repetition of small structures."

The 18th century and the 21st century singing, you might say, from the same hymn-sheet.

Opera Ireland presents Handel's Imeneo, directed by David Bolger and designed by Monica Frawley, at the Gaiety Theatre, Dublin, on Nov 20, 22, 24 and 26. The RTÉ Concert Orchestra will be conducted by Laurent Wagner