You mentioned your wish to understand the meaning of Bach’s music. For some scholars and performers today, the key to the meaning of Baroque music is musical rhetoric - the construction of a piece of music along the same lines as a classical speech, which was often discussed in Baroque treatises on music. Some musicians today regard musical rhetoric as a code, which allows for a translation from music to words. Nikolaus Harnoncourt is perhaps the most prominent advocate of rendering Baroque music as Klangrede (speech-in-tones). Other musicians and scholars suggest that this emphasis on rhetoric is exaggerated and misplaced. Where do you stand in this debate?

I think that as a method of analysing Baroque music, rhetoric is fantastic. Analytic methods from the 19th and early 20th centuries were developed with 19th century music in mind, and they don’t work so well when applied to Baroque music. Rhetorical theories, which were developed in the 17th and 18th centuries, provide a much better guide to understanding what the composer meant.

But after that, you still need to interpret the music in performance, and at that stage I am not sure that rhetoric is all that helpful. I am not saying that performers should ignore this issue entirely. My attitude is that, as a performer, you should think of yourself as an orator; you should communicate with your audience, put your ideas over to your listeners. But if the general idea of the piece is clear to you, then it does not matter much whether you go into rhetoric in greater or lesser detail. I don’t go very far into rhetoric, because I think it’s not very helpful for a performer. In fact, my impression is that the people who know the most Latin terms for rhetorical figures do not always know how to make music out of their knowledge.

My attitude is that, as a performer, you should think of yourself as an orator; you should communicate with your audience, put your ideas over to your listeners.

Rhetoric was only of limited use for composers as well. In Holland, a priest called Joannes Albertus Ban studied the music of his contemporaries and immediate predecessors - composers like Gesualdo and Monteverdi - and prepared a catalogue of figures and intervals that were appropriate for specific words. He then declared himself the best composer, because he knew how the great composers did it. But his contemporaries did not share this judgement. In 1640, there was a competition between him and the French composer Antoine Boësset; both composers were asked to set the same texts to music. The contest was presided over by Ban’s fellow priest and music theoretician Marin Mersenne, and by the Dutch poet Constantijn Huygens - both of them important composers as well. The two judges unanimously declared the winner.

I have seen the two pieces - they were published afterwards - and I agree with the judges’ decision. It might be true that Ban knew the rules of rhetoric better; he knew exactly which interval was judged as best suited to which word. But he could not do anything with this knowledge. He simply wasn’t as good a musician as Boësset, who occasionally ‘sinned’ against these rules - but nonetheless wrote a better piece of music. So it’s true that there have been musicians, both then and now, who consider rhetoric a sort of magic wand, who think that, if they know everything about it, they would be able to perform or compose well. But the magic doesn’t happen. So let’s be careful about this; let’s not to give it too much importance. But I don’t say it’s unimportant. It helps me to understand - but not to perform.