Bach’s Die Kunst der Fuge consists of 15 fugues (the last unfinished) and 4 canons, with no instrumentation specified - hence the subject of much discussion and controversy. The Fitzwilliam Quartet chose to play three of the fugues, beginning with the ‘simplest’, where the theme of the 14 completed fugues is presented. Communication was instant: as soon as Colin Scobie began to play the theme presented in the first fugue, Contrapunctus 1 there was a sense of gravity and purity of utterance, signifying that something important was afoot, and set the tone upon which the evening’s concert would be built. Contrapunctus 9 was full of urgent vitality, and the spectral chromaticism of Contrapunctus 11 took the quartet into unearthly regions of contrapuntal complexity. The three extracts made a very effective short suite, and it was a performance that never for a moment let you wish that this music was being played by other instruments.

Mozart’s Quartet No.1 was really rather a pleasant surprise, and provided a lighter note to the programme. Composed, apparently, in a tavern when Mozart was 14, it begins with an attractively lyrical slow movement, followed by an Allegro, a Minuet and Rondo, not quite the ‘normal’ order of things. The Fitzwilliams presented it very nicely, closing with a really winning little Rondo.

What was noticeable during the performance of these works was a specially rich depth to the sound, and the reason for this was explained by the quartet's viola player, Alan George, in a brief announcement to the audience, told us that the Fitzwilliam Quartet are perhaps unique in using instruments appropriate to the repertoire, playing on both historical and modern set-ups. For this concert and recordings of the works by Bruckner they had gone to extraordinary lengths and purchased hand-made gut strings as near as possible to those used in Vienna in 1879. He explained that the strings teach you a lot about how to play a work. There are things they won’t let you do - you cannot ‘throw the bow’ at the strings, for example, for short repeated notes, you have to make strokes, and many of Bruckner’s bowings that seem strange on modern strings now become obvious.

Bruckner wrote his quintet between the Fifth and Sixth symphonies, and it could be seen to announce a move away from the monumental style of the Fifth towards a warm and generous lyricism that characterises much of the Sixth and Seventh symphonies. The Intermezzo was composed as an alternative Scherzo for the Quintet as the original was considered too difficult by Hellmesberger’s quartet for whom it had been written. As soon as the Fitzwilliam Quartet began to play it you were aware of what a revelation these strings were for performance of the Bruckner Quintet. They have a full, rounded, rather smoky sound with a hint of roughness to them, but they are capable of wonderful resonance and sonority when all five sound together, such as in unison statements and the loud tuttis that end the first and last movements. In his programme note Alan George points out that Bruckner was able to achieve ‘glowing sonorities’ with an economy of scoring hardly achieved by any of his contemporaries, and this performance of the Quintet demonstrated that admirably.

In addition to this revelation of Brucknerian sound, the Fitzwilliam Quartet cultivated a flexibility of tempo and expression that moved the work far away from the idea of Bruckner as the hewer of rock-like monumental works. The opening theme, with its falling and rising contour, with its little triplet, responds well to expressive rubato, and Lucy Russell (1st violin) judged it perfectly. The continuation of the theme in pairs of falling quavers with trills is repeated very quietly - ppp - (the dynamics were clearly observed and graded throughout the performance) - and this moment displayed another virtue of these hand-made gut strings: even when played very quietly, they still speak clearly. The gruff and earthy Scherzo sounded really good, and when for four bars just violas and cello work away at the quaver motive that runs throughout the movement, it came over as a sort of delightful rugged rumbling, and set off well the contrasting transparency of the quizzical little trio.

Bruckner was the master of the profound and moving Adagio, and this one is amongst his greatest. Lucy Russell again presented the opening theme with full expression (exactly as marked ‘ausdrucksvoll’), and it was lovely to hear the second viola, James Boyd’s, brief imitative comment cast a slightly different light on the motive. Alan George introduced the second theme very beautifully indeed, with a wonderfully restrained tenderness which gave space for its more forthright repetition an octave lower by Heather Tuach’s always eloquent cello playing. The quiet closing pages of this movement were a testament to capabilities of the gut strings, the commitment of the players, and the profundity of Bruckner’s inspiration. It ended in rapt silence.

In his programme note George writes, ‘If the finale seems in any way problematic this can only be attributed to a failed attempt at making it fit into a conventional sonata form which it only superficially resembles.’ He then supplies an analytical sketch of the movement’s structure, and it was obvious from the performance that the players had no doubt how the music was built: they laid the movement out with wonderful and confident clarity, as though it were the simplest and most natural movement in the repertoire, but full of unusual effects, infectious Austrian dance, contrapuntal sophistication, and winding up to a rousing coda of splendid sonority.

It was a revelation to hear Bruckner’s quintet played on instruments with this gut string set-up appropriate to the time of its composition, and to hear it performed with a flexible lyricism that has become a rare thing in Bruckner performance. Although it didn’t take away from the inimitable idiosyncrasies of Bruckner’s style, it made the work seem altogether more natural, to sit more easily in the quintet mould. But above all this was a performance that communicated splendidly the work’s generous and tender heart and the profundity of its composer's vision.

It was received with enthusiastic applause by a packed house. Many of the audience will no doubt, like me, seek out the Fitzwilliam Quartet’s soon-to-be-completed recording of Bruckner chamber works when it appears.