For someone who has three productions in the current ENO season - Turn of The Screw, Mikado, and the deathless Rigoletto - this may seem the tiniest bit neurotic; but you have to remember that these productions are revivals. He hasn't done a new opera staging in this country for five years, in which time all his engagements have been abroad, lucrative but not always satisfying. Example: the Giordano Fedora he has coming up in Berlin, a notoriously third-rate opera which Miller is approaching without delusions. 'I'm a good mortician; and as a jobbing director that's what you have to be. Pieces like Fedora are your crocks of gold - except by definition they're likely to be crocks of shit, too - and when you stumble across one you make the best of it and use the money to do something you really want that probably won't pay anything at all.'
Something Miller has wanted to do for a long while and won't earn him a bean is happening this week in a church in Chelsea; and fringe as the project is, it marks in characterfully Milleresque manner the doctor's return to London opera with a piece that isn't actually opera at all. He is staging Bach's St Matthew Passion, which is an unlikely task for a Jewish atheist and a questionable one even for a committed Christian, in that Bach's Passions were not written to be staged. True, the ancient tradition of reciting the Passion narrative had a strong dramatic aspect to it; true, also, that Bach's music owes much to the form and structure of baroque opera, and that there are modern precedents for staging, including a traumatically old-style Catholic presentation in Paris by Pierre-Luigi Pizzi that spared no detail of blood and gore. But as a matter of history, Lutheran religion (as practised in St Thomas's Leipzig where Bach's Passions first took place) and the stage were antithetical. What's more, Passion music is largely static, contemplative and choral. So what is Dr Miller up to?
What he isn't up to is a stab at authenticity, despite the use of a baroque band conducted by Paul Goodwin, a period performance specialist. Miller is unimpressed by authenticity: 'It's not a way of getting closer to the past as people claim, because the past is irretrievable, we can't get closer to it. Authenticity is just a way of giving you a different kind of performance: a health food for the ear as opposed to the saturates you got before.'
Nor is he promising spectacle. No one will be scourged, spat on or crucified except, perhaps, in print when Dr Miller's critics stir themselves. 'This isn't going to be showbiz. All I'm trying to do is put some joints into a piece that gets immobilised by its normal method of concert presentation. Not everything will be acted; but the singers, sometimes the instrumentalists, will move around and react to each other as the music dictates. The idea is for something more intimate, more assertive and more direct in its address.'
It sounds like standard semi-staging. But Miller plans to make it more than that: an experiment in the kind of non-representational theatre he first looked at in his production of The Emperor at the Royal Court, which was effectively a sequence of journalistic monologues delivered straight, without adornment, to the audience. 'What I'm interested in is the relationship between telling and showing that isn't acknowledged by people who are so influenced by the emergence of scenic theatre in the 19th century and by cinema in our own that they think everything has to be representationally shown. It doesn't. There are other ways. And the Matthew Passion, which is a particularly subtle and intense form of discourse, suggests another. A way of making thoughts visible as well as audible.'
As for the Jewish atheism angle, Miller says it doesn't mean he reads the Passion merely as diverting fiction. 'Never underestimate the piety of atheists. Those of us who have no religious belief, who find ourselves thrown into the unsupervised affair of an empty cosmos with no captain on the bridge might still agree it would, as Hemingway said, be pretty to think otherwise. And that's more than sayingthe Incarnation is a nice idea. It's one of the greatest ideas, on a par with the invention of the wheel. It got things going. It extended the scope of human capabilities and our understanding of what it's like to be us. You'd have to be an insensible clod not to be moved by the Incarnation at something beyond the level of a story, seen as an atheist.'
And as a Jew?
'As a Jew it's painful, because you see in Passion narratives the origin of 2,000 years of persecution and conflict. Which is why I have contempt and loathing for religion.'
Will that be obvious from his Matthew Passion? 'I'm not out to generate a conflict of my own. You'll find that what we do is very reticent. I hope the audience will be touched by it. But if they come with expectations of polemic they'll be underwhelmed.'
'Matthew Passion' at Holy Trinity, Sloane St (071-730 1745), Thurs to 21 Feb.