For the past fortnight at the Wigmore Hall the Cherubini Quartet's first London Beethoven cycle has been convincingly reinforcing this precept. Partly it has been a matter of the stylish assurance of their playing. Chiefly, however, it has resulted from an awareness by all four players that the genre has its unique inner tempo. True string quartets unfold their ideas at a different rate from sonatas and symphonies. Transcribed for piano duet, they lose their sonorous essence. Beefed up in orchestral terms, they can sound fussy and rushed.
The D major quartet, Op 18 No 3, starting the cycle on 30 June with a statuesque, unruffled opening that soon boiled over into a flood of new thematic material, amply demonstrated the point. Understandably hesitant, the players took until the exposition's repeat to match their step in terms of intonation and cadential rhythm. But of their ability to grasp the music's pace - and to project the complex balance of its broader rhythm in terms of the medium itself - there was never any doubt. The lengthy first movement of the F major quartet, Op 18 No 1, showed similar, impressive unanimity, while the exceptional euphony of the group overall, centred around Harlof Schilchtig's glowing viola tone, proved the ideal vehicle for projecting the slow movement's theatrical pathos.
The G major quartet, second of the Op 18 set, had the players competing individually within its obsessive semiology of questioning and answering phrases. The result could have been arch, gestural; that is, without the Cherubini's measured sweetness softening its prim structural outlines. By contrast the scherzo was boisterously anarchic. And in a dozen bars of the finale, where cellist Manuel Fischer- Dieskau traced energetic lines against a sustained bare seventh in the viola, the ensemble probed textures of 20th-century austerity.
Even more of Beethoven the Progressive was on offer in the penultimate concert of the series on Friday, where the B flat quartet, Op 130, was preceded by its original finale, the Grosse Fuge. Miraculously, the Cherubini's reading of this hybrid avoided precisely that sense of exaggeration and strain that has always been proposed as the reason for presenting it in orchestral garb. Yet, with the rhetoric removed, it worked perfectly as a self-contained fantasy quartet, the players absorbed in the intimate relations of its contrapuntal web.
In the B flat quartet itself, where the patterns of dialogue from Op 18 No 2 seemed extended into paragraphs of sustained suspense and resolution, each return of the brooding introduction and allegro was a memorable dramatic event, culminating in a final transformation as a disembodied, spectral reminiscence. Both here and in the genial Alla danza tedesca there was more than a month's ration of memorable solos, exposed yet never forced. In the Cavatina, the singing tone and discreet vibrato of the leader, Christoph Poppen, allowed the composer's instruction 'molto espressivo' to speak for itself. The Beethovenian syncopations of the last movement were seriously comic. Even so, it was difficult to believe this was the last music Beethoven ever wrote.