William Christie and his multiple-award-winning ensemble Les Arts Florissants have developed a devoted audience all over the globe with their exciting concerts and recordings (over 70 at last count) of 17th- and 18th-century music, a repertory ranging from Gesualdo madrigals and Purcell odes to Handel oratorios and Mozart operas. Some of his stage productions (most notably one of Lully's Atys) have entered modern operatic legend. Yet most of all Christie is revered throughout the classical music world as the man who, more than any other individual, brought the music of the French Baroque back to life and made it viable for the modern stage and concert hall. Quite something for a Buffalo boy who went to Paris 30 years ago to study harpsichord.

Christie and Les Arts Florissants are spending much of 2002 touring their acclaimed production of Claudio Monteverdi's opera Il ritorno d'Ulisse in patria (The Return of Ulysses), which opens at New York's Brooklyn Academy of Music on 7 April. andante's Matthew Westphal spoke to him shortly before a performance of the opera in Caen about the challenges of bringing this 360-year-old work to life.

Matthew Westphal: The biggest question about The Return of Ulysses — the main question for anyone conducting a Monteverdi opera — is the scoring. For Ulysses and Poppea we don't have original scores, really, just a vocal line and a bass part from which the continuo players [harpsichord, lute, harp, etc.] improvise chords to accompany that line. How do you go about working that — just the voice part and the bass — into a performing edition?

William Christie: Arriving at a consensus with the musicians you're dealing with, first off. That's to say that you pick a group of musicians who believe the same way that you do, because they're going to have an awful lot of responsibility. Yes, you can flesh out a source like the Vienna source [a 17th-century manuscript in which Ulysses is preserved]; yes, there are things to be added to complete the material, but there's an awful lot that's there already. My point of view is that you do not have to sort of rewrite the score.

It's interesting that a month back, there were two productions of Ulysses in Switzerland, one in Zurich and one in Lausanne, and they had opened the same day — almost the same hour. One was a repeat of the Harnoncourt version done in Zurich ...

MW: You mean the old one that was televised in the 1970s, the one directed by Jean-Pierre Ponnelle that used a whole huge kaleidoscope of Baroque instruments?

WC: ... yes, the old one from many years ago, and the other one was mine. One of the critics pointed out the next morning that you weren't sure it was the same composer, let alone the same piece. Now with all respect due to someone like Harnoncourt, I think that just to say blithely, 300 and some-odd years after the fact, that we have to sort of help the score along — that it can't really speak by itself, that it's an incomplete, skeletal framework, one to which you have to add flesh and then clothes and then makeup and then what-have-you ... I don't believe that, really. I believe that obviously there was a strong element of improvisation; there could have been other composers called to do some of the less "noble" tasks such as writing dance music (although I don't really believe that's the case) and perhaps there were other parts, more than we have in the source.

MW: More than just the continuo line, you mean?

WC: Actually there are a lot of upper parts in Ulysses. You have a splendid collection of ritornelli [instrumental interludes], you have a splendid collection of accompanied arias. My idea is that you should leave an awful lot of this exactly the way it is. We're using a new score by [musicologist and conductor] Alan Curtis, though I've taken things even from Alan's version.

MW: What sort of things?

WC: Well, the Melanto aria "Ama dunque," for example, where he says that these little fragments of violin parts [in the source] are obviously to indicate that this is a through-accompanied piece. I don't believe that — I believe that the way the violins come in as echoes is very satisfying musically. It makes extraordinary sense (in my production at any rate) to play it just the way it's been put down on paper in the Viennese source.

I also believe that [music with only] traditional continuo is not an arid moment where you're longing to hear violins and sacbuts and flutes and shawms and whatever else that you can stick in. Continuo, when it's played correctly as an improvising band, can be as exciting as anything that you can orchestrate with other instruments. And then that makes for these wonderful halos when the violins do come in to accompany — which suggests that the piece that they're accompanying is very, very special in its dramatic and musical content.

This means, of course, that every member of this small orchestra that's touring all around Europe and the States is a very important part of the group. We have two lutes, two harpsichords, a lirone, a harp, three bowed bass instruments, a dulcian [early bassoon] — and then we have a solo first violin and second violin, violetta, two cornetti. This is rather large for a Venetian theater of the 1640s — we could certainly have done this piece with even less. But I don't believe in the overkill that we're coming back to with a lot of Baroque people; Harnoncourt did his version 30 years ago, and we have other colleagues who three years ago have been doing pretty much the same thing. Even to the point of writing out the continuo.

MW: Your continuo players are all experienced in realizing bass lines ...

WC: Absolutely — I've been playing with them for 15 or 20 years.

MW: How about the melody instruments — the violinists and cornettists? How much of their parts are they realizing (or have they realized) themselves?

WC: They're playing extremely faithfully to the source. There's been no added material except for the end of the second act, with the ballo, which we've translated into a three-part canzona for voices. So essentially the answer is nothing — except for noise, and sometimes colla parte playing [doubling vocal parts] to change color.

MW: How carefully do you plot out the realization of the continuo in terms of instrumentation and the like?

WC: Every note.

MW: That is, "harp is playing here, lirone there, etc."

WC: Every note. It's just like a jazz band — pre-arranged, you do this and I do that, whatever. It's a Duke Ellington orchestra of 1929 in the sense that you've got a lot of common bass, but you've got Billy playing here, Jimmy plays there, I don't play there ...

MW: Do you play much of the continuo yourself?

WC: Of course. If the piece is conducted, then the piece is dead.

MW: What factors govern you when you're deciding which continuo instruments to use where?

WC: It's the sense of the words and the dramatic sense. You begin with something so basic as loud and soft, given that you have a continuo that can play from pianissimo to fortissimo — that's the most basic sort of thing. When you have the whole band playing, there's something really important going on onstage and it's loud. Other than that, you have immense color effects ranging from solo harp, to two harpsichords playing together without anything else, to concerted effects where the bowed basses are actually forming chords to accompany sinister passages. It begins very early on with the continuo people working with the drama coach, with the language coach — which is a far more important thing to do than just working musically — and it happens much before we do any of the stage work.

And then after that there's a third consideration — it's spatial. You have a pit, you have a harpsichord to either side, you have the continuo instruments spread out the entire width of the stage. Why do I do that? Well, there is iconographical evidence that suggests that it was like that, and it's extremely good for the singers. And that means that there's a left and a right and a middle, depending on the action on stage.

MW: Do you find, compared to the French opera with which most people associate you, that Monteverdi is less structured or structured in a different way?

WC: Oh, it's a different world — first of all it's a different world linguistically. What they have as a common denominator is the fact that they're language-obsessed. Why is Monteverdi writing the way he does? Well, it's to set some fairly lovely libretti into recitative — just as Lully and his contemporaries and successors are working with French classical theater. So they're two moments in musical history where words are as important as music, but other than that there are worlds of difference.

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