Paradox is the crucial thing about Bach and it probably was always with him. But if you find a paradox, you should not necessarily try to understand it logically. The essence of a paradox is that you can’t understand it and if you want full value from it you must accept it for what it is without too much analysis. And that’s the richness of paradox, because it goes beyond our normal thought processes. So we don’t need to attempt to reconcile these two sides of Bach; he did it himself. Bach had an old-fashioned sense of structure and he also, although not very frequently, wrote modern music, of which he was a master. The secular cantata “Phoebus and Pan” [BWV201] provides a good example. Bach has Phoebus sing in “learned” style and Pan in simpler, more popular style. Any other composer would have arranged it so that Phoebus emerged as a clear winner in their singing competition, but for Bach both are very good, if quite different. Of course we know that Bach was in favour of the more old fashioned and complicated “art” style, but even the aria he gives to Pan in the competition is a fantastic example of its particular style. He could do everything.

That’s a work in which we encounter Bach as an effective dramatist, an aspect of his musical personality that is frequently overlooked. Could he have been an opera composer, if, for example, he had moved to Dresden and had the opportunity to do so?

I think he could, although I don’t believe he was aiming at Dresden in order to write operas. He wanted a secure post and the commissions that were possible from Dresden. But his secular cantatas, the dramme per musica, are outstanding and he understood rhetoric better than virtually anyone. But anyway the St. Matthew Passion is also a kind of opera and structurally all the cantatas are miniature operas, although they don’t of course have any action. Speaking of that, I am very much against attempts at staging the passions. It’s a horrible affair and nonsense. I would pay not to be obliged to attend such events.

I totally agree and it’s a topic we could probably talk about for a long time, but let’s for the moment talk more specifically about the instrumental works. Inevitably that means above all the solo violin partitas and sonatas, which have become so associated with you through the two recordings you’ve made of them. The first was made in 1981, a time when period style was still in a relatively evolutionary phase. You must have been conscious that it was a remarkable pioneering effort. Looking back do you recall any special difficulties with works that represent a huge challenge to any violinist?

I knew it was necessary to do them, but it was not easy. I had only started to change my violin technique between 1969 and 1971, when I started to adopt what people call “chin-off” playing, a technique I’m still using for playing and teaching. It was a very important period in my development as a musician.

For the benefit of those who might not understand it, would you briefly explain what the “chin off” style is, please?

What people normally do today is hold the violin between the chin and the shoulder.