The term ‘performance practice’ has by now become just as charged and easily misunderstood as the word ‘authentic’. When considering the various performance practices of early twentieth-century compositions by early twenty-first-century performers it is hard to find a common denominator. Even when identical sources (scores and professional literature) are consulted, essentially different interpretations will emerge. Interpretations are the result of a wide variety of complex, often indefinable factors that are part of the highly subjective make-up of each individual musician. The interpretation of a composition by a string quartet is, by definition, the fusion of ideas of four individuals. It has been suggested that the Schoenberg Quartet aims for a playing style that could be identified as ‘authentic’. This is not the case. As for possibly ‘historical’ aspects of our performance practice, only our positioning with regard to one another, the occasional use of special mutes and certain views on vibrato could be said to hark back to the past. In our sessions with Eugene Lehner we never attempted to play like the Kolisch Quartet. Incidentally, Kolisch and Lehner were quite dissatisfied anyway with their recordings of the Schoenberg quartets, which were recently released on compact disc with the word ‘authentic’ – so hated by the Kolisch Quartet – slapped on them. In our view, their interpretation is still unsurpassed, and it is hard to imagine anyone trying to imitate their style, let alone succeeding in doing so. We do know for sure that Schoenberg was very pleased with their interpretation, as he was with the playing style of the young Juilliard Quartet, who played the quartets for him in the late 1940s.

In our opinion it is very important to find the most reliable editions of the works we play. This is easier said than done, for the quality of editions varies widely. For example, Janácek’s First String Quartet has been edited in an exemplary manner by Milan Skampa, violist of the Smetana Quartet, but we are still impatiently awaiting the appearance of his revised edition of the same composer’s Second String Quartet, Intimate Letters. Reliable editions of the quartets of Debussy and Ravel – part of the mainstream repertoire for a over a century now – simply do not exist. In the score and especially the parts for Ravel’s quartet we have six hundred major and minor corrections, mainly as a result of discrepancies between score and parts. Sometimes the printed parts prove more useful than the score, in most cases it is the other way round. The composers often had no opportunity to see their works through to a second edition. In such cases the annotated scores found in the composers’ estates often turn out to be quite enlightening.

Early teachers of the members of the Schoenberg Quartet such as Frans Vester, Frans Brüggen, Anner Bijlsma and Sigiswald Kuijken instilled in us a healthy dose of suspicion with regard to printed music and encouraged us to critically study all sources available to us. Even within the oeuvre of a single composer there may be significant distinctions: for example, in the case of Webern’s works that have opus numbers there is hardly a misprint to be found; the editions of his posthumously published works, however, are shambolic and the only available option is meticulous study of the manuscripts, which are kept in libraries in Basle, New York, Washington and several other cities. That way wrong notes, wrong clefs, missing dynamic markings, phrasings and even missing measures soon come to light.

The study of Schoenberg’s music for strings is also problematic. Although several editions of a work often exist, in many cases the parts are available only in first editions, some of them a hundred years old. In general the Gesamtausgabe of Schoenberg’s works offer better scores but, alas, no parts. Moreover, even these scores are far from faultless, not to mention the dubious practice of correcting notes of dodecaphonic works according to numerical tables, even though Schoenberg himself did not correct them. Lehner once told us that Schoenberg, whenever asked about a possible mistake, always stuck by the notes in his manuscript. The Schoenberg Quartet use their own ‘editions’ that are mainly based on manuscripts and the Gesamtausgabe. Thus we make our own decisions about how to deal with the problematic passages of each composition. In the case of Verklärte Nacht, for instance, the painstaking comparison of the version for sextet and the 1943 orchestral version proved extremely fruitful. Also of great interest to us was the score of the Second String Quartet in the Gesamtausgabe – which includes instructions by Schoenberg intended for a performance by a string quartet that was unknown to him. It is fascinating to see the composer change tempi and phrasings soon after composing the work, and to read his extremely precise explanations as to how he wished his music to be played.

The most rewarding performance practice arises when we have the privilege of working together with a composer. We often find that composers have a free approach towards their work and sometimes such collaboration leads to a revision of certain tempi, phrasings, bowing indications and the spacing of chords. These inspiring processes as well as Lehner’s useful advice have often led us to decide – though not without some reserve – to rearrange certain unfortunate spacings in, for instance, works by Debussy and Schoenberg.

A good example of what we consider a successful performance practice was the quartet’s revised reading of Schoenberg’s Ode to Napoleon Buonaparte. Since the very first performances of this anti-dictatorial masterpiece the reciter’s part has invariably been rendered by singers (Schoenberg wrote mockingly to Kolisch that a ‘musical singer’ was required for the part!). In our view the expressive recitation of Byron’s poems according to Schoenberg’s concept of ‘Sprechgesang’ can only be accomplished by an English actor. Moreover, a Dutch translation of the text as well as extensive programme notes elucidating the work’s many references to rulers from the past are absolutely essential. The efforts and achievements of the actor Michael Grandage and Byron expert Joop van Helmond in this project exceeded our wildest expectations. The whole process proved once again that it is rewarding not to choose the path of least resistance. In other words, although opting to do without a conductor and employing an actor instead of a singer may have increased our difficulties, we did come much nearer to realizing our ideals.