My first encounter with Bach was as a boy of seven or eight, when like other children I tried to play things like the 2-part Inventions and the little preludes. I was fascinated by something that I could not of course then identify, because I was too young. But I was struck by the fact that this music seemed to be different to everything else. That has never changed; it is something that has always stayed with me. Naturally I see Bach as part of his time, but always with the feeling that he is not the same as his contemporaries.

Yes, I think this raises an important point. If we hear the music of a Telemann, a Stöltzel or a Graupner, we can see that they are essentially coming from the same place, but you can’t do that with Bach. Can we define a recognisable “Bach style” and what it is that distinguishes him from his contemporaries?

Well, I think we can at least partially place him in that context. When you talk about style, much of Bach’s style is in fact similar to that of Telemann and his contemporaries. In his later life, for example, he does things that are very similar to his son Carl Philipp. In fact the third movement of the Trio Sonata in the Musical Offering is for instance very Rococo. And there are other examples that could have been Sentimental if they were not by Bach. They are at the edge. But even in such pieces that on paper look quite similar to the music of his contemporaries, there is another more profound dimension. There is something strange that Bach shares with Mozart. It appears that their music has a deeper source. I know it’s a romantic idea to say that, but I’m not ashamed to do so and in fact I feel it increasingly.

A strong spiritual element is so often discerned in Bach’s music. Is this a part of what you’re saying?

I think it is. And the spiritual aspect has nothing to do with whether the music was intended for the church or otherwise. It’s a quality you will also find in the instrumental pieces. The most obvious example is the Cello Suites, because of the tessitura of the instrument, which is so similar to the human voice and doesn’t have that kind of shrill tessitura you get with the violin, which is much more ambitious. It is not as generous an instrument as the cello or gamba. In the suites and sonatas for those instruments, and some of the ensemble music such as the 6th Brandenburg Concerto, the low sonority serves to increase the spirituality of the music.

If I understand you correctly, you seem to be saying that you can define the degree of spirituality in Bach’s music in terms of pitch.

No, no, but I think you are more likely to find it in a piece that has complete harmony or a low point of density, rather than in some of the solo violin works. You need a bass to connect with what we call the spiritual. That might be nonsense, but that’s the feeling I have. Having said that, you then have “Aus Liebe”, the soprano aria in the St. Matthew Passion, which has no bass and is the most incredibly angelic music!