Juliane Banse and András Keller made the seminal recording of Kafka Fragments in 2006, on new music label ECM. Kurtág himself worked with them and was present throughout the recording so it's almsot definitive. So hearing Banse and Keller perform it live at the Wigmore Hall, London this week was a salutary experience.

Kurtág’s music needs specialized, well-informed performance. It is deceptively simple on the surface but requires highly intuitive interpretation. Because he writes aphoristically, his miniatures seem simple. But Kurtág likes puzzles. His music opens out like a complex maze entered through a tiny door. Its secrets lie not so much in what’s on the page, but what’s not. His notations are unorthodox, so it can’t be followed on autopilot. Instead, Kurtág’s performance depends on the innate musicality of those who perform the work, and how well they intuit his idiom.

Most music only “becomes” music when played by those who understand what’s happening, but much more so with an idiom as elusive as Kurtág’s. For all the inventive freedom and whimsy he embodies, Kurtág’s music requires superlative discipline and attentiveness. The Wigmore Hall recently hosted a series of workshops on Kurtág led by Julian Phillips, where artists of the calibre of Marino Formenti and Rolf Hinds discussed their experience of working with the composer.

Kurtág’s Kafka Fragments are intense, homeopathic distillations of ideas from Kafka’s letters and diaries. The gist is that they are “fragments” not whole quotations. What is not said is every bit as important as what is. Meaning doesn’t depend on words alone; hence the absolute importance of well-informed, intuitive performance. András Keller has worked with Kurtág for decades and is one of his primary interpreters. He heads the Keller Quartet which has performed many Kurtág works, and knows the composer's idiom thoroughly.

Indeed, the very idea that the Kafka Fragments are a song cycle is misleading. Hearing Banse and Keller interact live, showed just how much the work is a delicately-poised balance between singer and player. Primarily, it’s a musical dialogue, for Kurtág’s expression comes from the way he sculpts sound and uses intervals, regardless of whether the instrument is voice or violin. Text setting this isn’t, rather a sophisticated use of sound and silence to evolve an impressionistic panorama of diffuse feelings and ideas.

The first sound you hear is the violin, creating a swaying zig zag. Like a door swinging open? Banse’s voice enters, completely in synch with Keller’s playing. Die Guten gehn in gleichen Schritt, personified. Significantly, the nest line refers to “others” who dance around them, unaware. Immediately, Kurtág establishes a sense of movement and purpose. Perhaps the central image in the Kafka Fragments is that of an esoteric pathway, deliberately obscured. The violin soars in wild frenzy. Banse simply has to speak the title of the fourth song, Ruhelos. No need for elaboration. The “song” happens when Keller comments, without words.

Keller and Banse bring out the musicality in the piece to an extraordinary degree because they understand the internal logic. For example, Banse leaps up and down the scale within the words Nimmermehr, Niummermehr. By replicating the swaying zig zag with which the violin began the piece, she’s showing how the structure of the work is evolving. It’s a quick Ruckblick befiore the next stage in the journey, In the next fragment, she sings “Immer, Immer”, with a similar but subtly different sweep: voice as violin again. Keller’s playing intensifies the wild swings, Banse’s voice responding with force. Then, suddenly silence.

The two Berceuses aren’t restful, even though they refer to sleep. Quietness doesn’t mean repose. Intervals are carefully placed so the word “Aufgewacht” leaps out. Banse spits the word out almost in a single syllable. Her voice sounds like a violin string being pulled tautly. Vibration but tightly controlled. Ticking patterns, as Keller taps bow against the neck of the violin. Banse sings staccato, not sharp but resonant, like wood on wood.

The idea of voice/violin balance is further explored in the fragment that refers to Balzac. Banse enunciates the first words in each sentence, with vaguely Sprechstimme deliberation, but leaps in tune with Keller’s violin on the word “Hindernisse”, both times it’s repeated. Another echo of the swaying imagery. Then the violin creates a bizarre sound like that of a door that has long been closed stiff, being slowly pried open. A metaphor? Entirely apt.

Keller unleashes brilliantly virtuosic leaps and elisions. The singing becomes abstract,, following the patterns in the music. The last thing you’d want to hear here is a voice as “persona”, I think, for what matters is the smooth integration of two instruments, one string, one wind. This intense intimacy reminded me of the way Kurtág and his wife Marta play together, as if they’re a single organism operating in two halves. Banse turns Keller’s sheets for him so he doesn’t miss a second, which makes a difference in music as finely poised as this. Although the gesture is made without sound, it is very much part of the true meaning of the piece.

Then just as you’ve got into the elliptical vibe, Kurtág cuts it off. Tapping sounds, the word “Nichts” squeaked shrilly so it doesn’t sound human, but violin like. “Nichts dergliechen”. Take nothing for granted.

The second part consists of a single song in the piece, though there are barely three lines in the text. Keller’s playing is exquisite, for this is a stage in the journey that must be savoured. The violin dominates, with a languid almost-melody that snakes round the voice. The Kafka Fragments aren’t just a dialogue between voice and violin, but between two violins. Keller’s primary instrument has a bright, positive timbre, while the second is warmer, more languid. Because Keller’s playing is so subtle the difference is remarkable.

More musical puzzles. In the third section, violin and voice imitate other instruments. In Schmutzig bin ich, Milena, the violin sounds relatively conventional, imitating voice. The words refer to dirt and cleansing but that’s deceptive. Most of this fragment is taken up by the image of voices in deepest hell. Specifically, the text says that what we take for the song of angels is the song of the doomed. Later, Banse’s voice sounds like a clarion bell, or murmurs like an oboe, and the violin shimmers like an ethereal flute. The words “Aufgewacht” surface again. Pay attention, and to the underlying seams that course below.

The mood in part four changes again, taking up the languid stillness of part two. How Keller’s violin seems to wail, as if in mourning. Then, suddenly he reverts to notes plucked at spaced intervals, and awkward, angular scatterings in contrast to Banse’s fluid lines. Part way he changes violins again, augmenting the disconcerting effect. Banse’s voice swoops wildly: Leoparden brechen in der Tempel - what an image, hinting at some unknowable savagery. Yet immediately after, another Kurtág contradiction. “Ich kann…(long pause) nicht eigentlich erzahlen” (I can’t…really tell a story). The hesitations in the intervals, and in the text underline the idea that Fragments cannot tell a story. Proof, if any were needed, that Peter Sellars’ staging of this work was an anti-musical abomination. Avoid it, even in audio, as the balance between voice and violin is all wrong.

Kurtág ends equivocally. Wiederum, wiederum, round and round, like a circle. Banse’s voice and Keller’s violin twining round each other. But it’s the final fragment that opens out onto new vistas. Es bendetet uns die Mondnacht : moonlight casts spells, transforming daytime reality into something magical. Otherworldly sounds from the violin, part gypsy demonry, part Jewish lament. Banse’s voice traces huge, expansive shapes that extend the idea of circles spreading outward. As her voice goes quiet, the ripples resonate endlessly into the void.

Perhaps this wasn’t Banse and Keller’s finest performance, for which I can’t blame them.The house was half empty, unfortunately, as there were major opera premieres the day before and after, drawing away the audience. But it was a wonderful masterclass that showed why Kurtág’s Kafka Fragments are so remarkable. And believe me, even not at their best, Keller and Banse are way ahead of any competition.

Anne Ozorio