The first edition of Beethoven’s Kreutzer Sonata described it as ‘scritta in un stilo molto concertante’, and the problem for modern interpreters is deciding exactly how ‘concertante’ one dares to go. Clearly this is a virtuoso work, charged with the outsize personalities of its first interpreters, George Bridgetower and Beethoven himself. Equally clearly, though, the violin and the piano have evolved and diverged since 1803, creating serious problems of balance for a modern-instrument interpretation.

The glory of Frank Peter Zimmermann and Martin Helmchen’s performance is that neither player sounds as if they’re holding back. Helmchen plays (as he has throughout this cycle) on a Chris Maene Straight Strung Concert Grand, an instrument whose transparency works miracles in terms of balance and texture, with both players naturally audible even amid the whirlwind passagework of the first movement. There’s an electrical charge to this reading; an ever-present sense of the music’s latent rhythmic energy, conveyed through Zimmermann’s taut, lean lower-register tone and almost improvisatory flights, but equally present in Helmchen’s poised and subtle phrasing.

That makes for a thrilling Kreutzer, but also a delightfully skittish and gleeful Op 30 No 3 and a thoughtful, often imposing reading of the late Op 96 Sonata (described, curiously, as being in G minor; a rare error by BIS). But these qualities never exclude delicacy, often of the most exquisitely poetic kind. Listen to the way the two players seem to lift and revolve the theme in the light shortly after the opening of Op 96 – the sound glints and almost dissolves. Beautiful playing, keen but lightly worn intelligence and an unflagging supply of Beethovenian energy make this a fine conclusion to an invigorating and highly rewarding cycle.