Enter at this point Alexander Goehr, whose Arianna has presented him with an even trickier conundrum. The libretto of his new opera, telling of the abandonment of the mythological Ariadne by the perfidious Theseus on the island of Naxos and her subsequent (unrequested) "rescue" by Bacchus, has been written by an Italian poet named Ottavio Rinuccini. It is a beautiful, stylish, and dramatically concise piece of work. The problem? Rinuccini died in 1621.
The creation of the first known opera on the subject of Ariadne (many have followed, most famously Richard Strauss's Ariadne auf Naxos) is an intriguing story in itself. The gradual birth of the musico-dramatic genre we now call opera took place around 400 years ago, in a world whose artistic perceptions were in some ways different from our own. Nowadays, when a composer decides to compose an opera, he or she usually works with a librettist whose main function (whether they like to admit or not) is to satisfy that composer's requirements.
In early 17th-century Italy, by contrast, the cornerstone of the operation was considered to be the poet and his text, which the composer then set as was required of him. In 1608, a sensationally talented 41-year-old called Claudio Monteverdi, then a musician at the ducal court of Mantua, was asked to compose an opera on Rinuccini's Arianna to celebrate the wedding of one of the Duke's family. The work was rated a success. Yet, while Rinuccini's libretto has survived, Monteverdi's score is lost - with the exception of the "Lamento d'Arianna", the extended, poignantly beautiful aria in which the composer so exquisitely captured the heroine's despair at her abandonment.
Apart from the chance that there's a mad collector somewhere in the world who nightly gloats over the sole surviving copy of Monteverdi's score, we have to assume that we'll never know how the rest of the opera sounded. Goehr's Arianna thus sets foot in a world that hums with strange and fascinating possibilities.
He has set the libretto broadly complete in its original Italian, and has also used Monteverdi's surviving fragment - essentially Arianna's vocal line and the orchestral bass part - as the basis for his own musical elaboration of her immortal "Lamento". Curiouser and curiouser: Goehr is a composer whose musical language is rooted largely in the modern Austro-German tradition exemplified by Schoenberg. And Schoenberg's music isn't normally considered to sound too much like Monteverdi's.
The situation of a modern composer turning to the music of the past is nothing new. Luciano Berio took the third movement of Mahler's Second Symphony for the central movement of his Sinfonia of 1969, duly triggering spectacular creative results of his own; more recently he used surviving sketches of Schubert's projected 10th Symphony as the basis of his own orchestral Rendering. As Goehr says, he too is unconcerned about any theoretical issues of stylistic anachronism.
"There's a sense in which theatre is always of its day. And besides, it wouldn't be true to say that the whole idea started from my thinking about the libretto. There'd been a change happening in my music for some time before then. The real roots of the idea go back even further."
Goehr's father Walter, the German-born conductor, led the first-ever complete performance of Monteverdi's Vespers in England. "Singing in that was a life-changing experience for me. There are times when you just get bowled over by something, and that's that. So composing Arianna was a very personal response. I couldn't have done it if it had been a fragment by Purcell, for instance."
Fine: but how can a modern composer effectively imagine himself into Monteverdi's shoes? "It was a problem until I invented Gruenberg," Goehr says with a roguish smile, allowing me just enough time to realise that Gruenberg is German for a certain Italian composer beginning with M. "This was my way of impersonating Monteverdi."
Arianna's producer is Francesca Zambello, whose reputation in these islands is rightly sky-high after her stagings of Puccini's La Rondine for Opera North in 1993, Mussorgsky's Khovanshchina for ENO last year, and her recent Billy Budd at Covent Garden. Coming up for air between rehearsals, she was keen to stress that monumental epics like Khovanshchina aren't her only speciality.
"When I was starting out in the States, I did a lot of smaller-scale Baroque opera. Also I was working mostly in straight theatre at that time and there are ways in which Baroque opera is close to that. The way it explores intimate emotions, for instance. With Arianna, we had to decide early on how to make that intimacy come across in a large auditorium. American opera houses tend to be huge, so Covent Garden feels quite intimate to me. But it's still a lot bigger than anything Monteverdi would have had in mind. His Arianna was performed at the end of a large room, with hardly any scenery, and our set too is quite spare. We do have a few gods and goddesses flying about. But in Mantua they'd probably have staged it like that if they could. Also we've put the orchestra and conductor with the singers on the stage."
"We were keen to get beyond the stereotypes," Goehr explains. "We decided that Venus, the goddess of sensuality, should be a mature figure for once. There's no reason why she has to resemble Marilyn Monroe, so we've made her a contralto. Bacchus too is different from the heroic tenor of Strauss's Ariadne. We decided he was more androgynous than that, so he's a counter-tenor."
For Ariadne's apotheosis at the end of the story, something closer to modern sensibilities ideally needed to be found. Looking for clues in contemporary accounts of those first performances of Monteverdi's Arianna in Mantua, Zambello discovered something to combat the inevitable accusation - that setting an Italian late-Renaissance opera libretto is somehow intellectually archaic.
"The women in the audience obviously discussed it afterwards among themselves. We can tell this from some diary entries that have survived. The consensus was that they were more interested in the idea of Ariadne resolving her situation for herself, rather than Bacchus turning up uninvited and doing it for her. They thought that was condescending." This was how a contemporary court audience was discussing a new opera 387 years ago? "Absolutely. And you can't get much more up to date than that."
n `Arianna' opens 8pm tonight, then 18, 23 (R3 broadcast), 28 Sept, 4 Oct, ROH,Covent Garden, London WC1 (0171-304 4000)Reuse content