​For the third time, violinist Liza Ferschtman will enter into a dialogue with Johann Sebastian Bach. In Utrecht, The Hague (at Classical NOW! on Sunday evening 18 December) and London, she will play his Sei Solo a Violino senza Basso accompagnato, better known as the 6 Sonatas & Partitas for solo violin. In Bach's eyes, man was created in God's image. For this reason, he signed his compositions with Soli Deo Gloria ('to God alone be the honour'). This phrase reflects his belief that those who deeply engage with his divine music can connect with the creator through sound. By immersing themselves in his compositions, listeners can ascend to higher and deeper levels of understanding and communication with the divine. According to Goethe, all of Bach's music sounds 'as if die ewige Harmonie sich mit sichselbst unterhielte.' Ferschtman thinks the same and explains what Bach's 6 Sonatas & Partitas mean to her. 

​​In search of perfection    
​You are now embarking on your third cycle of the 6 Sonatas & Partitas. What fascinates you so much about this music and do you keep going at it 'forever' ? 
'To answer the second question right away : Yes ! Is it a fascination ? No, not even that per se, you just know and feel that there is always more to discover. Your perspective also changes. Your taste develops and your sense of tempo fluctuates over the years. That applies to all good music, of course. But with Bach's solo works, the special thing is that you can create music on your own that is so incredibly complete. And even more so in the polyphonic parts. It's great to be in control of the voicing on your own, as if you were a pianist or a string quartet. That actually gives infinite possibilities. In no other series of solo works is this the case. For instance, I sometimes try to take apart the double stops in 6 Sonatas opus 27 by Ysaÿe in order to follow the voicing properly, but this is far from always logical and correct. I still experience this as a bit disappointing. With Bach, everything is always perfect.'  

When did you first play Bach's Sonatas & Partitas and what has changed in the way you approach these pieces since then?
'I played the Prelude in E major first, I must have been about 11 or 12 years old. When I was sixteen, the Sonata in g minor was added. Surely the change over the years has been great. Apart from the fact that as a child you usually still have a somewhat limited technique and world of experience, I still came from the 'romantic' violin school. I remember as a 16-year-old I thought someone like baroque violinist Sigiswald Kuijken sounded ridiculous. Now I myself have moved much more in the direction of authentic performance practice.' 

​Which musicians have you studied with to learn more about Bach's music?
'The first one who opened my ears more was recorder player Walter van Hauwe. When I was about 20 years old, as someone who didn't think like a string player, he showed me how there could be more fun and rhetoric in Bach's music. He taught me that vibrato is not a given, but should be put to useful use. That was an essential turning point. Around that time, Rachel Podger also released her Sonatas & Partitas on CD, which also gave a new perspective. But I still had a long way to go. Some time later again, about ten or eleven years ago, I started playing for Anner Bijlsma, which set everything in motion even more. 'Speaking' in music now became much more the goal. His book on the Bach Senza Basso has also given me incredible tools. You can get wonderfully lost in certain details through it. Bijlsma sometimes goes very far in interpreting every just-not-hundred-percent-finished bow in the facsimile of the Sonatas & Partitas, but it creates even more possibilities in the endless search. I also worked with baroque violinist Lucy van Dael, which helped me too!' 

'Authentic' sound  
You call yourself a 'hybrid violinist'. Gradually you switched to a baroque bow and perhaps gut strings. You also opt for an extra low tuning. Why?
'A baroque bow helps with articulation and gives more manoeuvrability. Such a bow is simply not made to facilitate only a long lilting line, as the modern bow is more aimed at. Certain other aspects that fit into a more 'authentic' style are also easier with a baroque bow. But it certainly still happens that I do play Bach with a modern bow in between. Getting the polyphony out of it is not necessarily a matter of the bow; I have learned that this is something you have to know and hear incredibly well yourself, only then are you able to pass it on to the listener. I learned this from Sokolov, when I heard him play a Partita by Bach in the Great Hall and the grand piano sounded so extremely in stereo.  ​I had never experienced anything like that before. That made me realise that it was the power of his inner ear - in addition to his incredible piano technique, of course. Thanks to Sololov's inner ear, it could be so bright !  
In terms of tuning, there is no golden rule. Apparently, the organs in Köthen were tuned around 440, so it is not at all necessarily necessary to play at 415, but I do like it on my 'modern' tuned Guarneri to get extra relaxation in the sound with a low tuning. It helps me. At the moment, I don't play Bach exclusively on gut strings because I play too much other repertoire in between. In that case, low tuning gives me just that little bit of extra 'authentic' sound. In fact, over the years I have become very much a fan of the sound of gut.'  

Ultimately, should Bach 'sing' or 'speak' or 'dance', and how do you feel about vibrato and other freedoms (rubato, region, accents, etc) ? Is there room for 'improvisation' ? And why do you play this music with Bach's original manuscript on your music stand ?  
'There is certainly a 'singing' Bach, but in the Sonatas & Partitas, 'speaking' has become the most important thing for me. Apart from dancing, as far as the Partitas composed of dance parts are concerned. Vibrato, even in romantic or modern style, should be something we don't use on autopilot. That's actually the most important thing, that it always starts with the tone taken out of the instrument by the bow and then vibrato can augment that tone where necessary, as it were. For additional expression. Improvisation in the sense of adding embellishments to repetitions is certainly possible with Bach, there is absolutely room for that. The fact that I always play from the manuscript is due to Bijlsma, who said that it brings you closer to the man and his music. Also because Bach's music, as already indicated, is a treasure that keeps on giving, there is always something new to discover. I can't go back!'