The Barcelona-based Cuarteto Casals have already made a very distinctive mark in quartets by Haydn, Mozart and Schubert. Now, having circled the base of Mount Beethoven, they begin the ascent, with the first release in a full cycle to be completed in 2020. This first volume deals in beginnings and endings: starting with the Quartet in F, Op 18 No 1, containing the Mozartian Op 18 No 3 (supposedly the first that Beethoven composed) and finishing with his last completed quartet, the extraordinary Op 135 – also in F.

The immediately striking thing about these performances is the sound. Cuarteto Casals play on modern instruments but they’ve assimilated the lessons of historically informed performance – swift tempos, dancelike articulation, the use of vibrato as a sparingly deployed expressive colour – and incorporated them into performances of fleet-footed conviction. The group own a collection of Classical-era bows; while they don’t say if they’re using them here (the booklet contains no biographical information), it certainly sounds as if they might be.

The ensemble tone is silvery and transparent, with ringing, resonant tuttis (the recorded balance is lively and slightly favours the top and bottom registers) and textures of real clarity in contrapuntal passages. There isn’t a massive sonority in the whole set; in fact, if I had to choose one word to describe these interpretations, it would be ‘classical’. There’s certainly a sense that the Op 18 quartets are contemporary with late Haydn, and there are moments – the throwaway opening of Op 18 No 1, for example, or the way the march rhythm rises playfully to the fore in the Adagio of Op 127 – when Beethoven’s inspiration can seem disarmingly light.

What becomes clear, however, is that in each quartet the Cuarteto Casals have identified a climactic point and focused the entire interpretation around it. So in Op 18 No 4, the Minuet acquires an almost symphonic weight. The sweeping cello solo that opens Op 59 No 1 is not an end in itself but the understated beginning of a process that finds torrential release (after a slow movement of steadily mounting emotional intensity) in the finale. Similarly, the glorious Lento assai of Op 135 serves as a prelude to the ‘Muss es sein?’ finale, which they play with fierce brilliance. But there’s no loss of poignancy or tenderness in that great slow movement; rather, a heightened sense of anticipation.

Throughout, the group are playfully subversive with rhythms: giving the opening gesture of Op 127 a destabilising kick and making Beethoven’s own transcription of the Piano Sonata Op 14 No 1 (a rarity even for a ‘complete’ Beethoven quartet cycle) move with quicksilver fluidity. Nothing in this set is quite what it first seems, then, and the same restless, forwards-moving energy pulses through even the gentlest bar. The Cuarteto Casals’s sound world won’t be to all tastes and I can think of interpretations that go deeper and darker. But these are performances to provoke, to amuse and to refresh jaded palates. It’ll be fascinating to hear the next instalment.