BACH'S SIX SUITES for solo cello are - understandably - often referred to as ‘the cellist's bible’; but actually, our bible, like the other, somewhat older one, consists of two books. The second comprises Beethoven's sonatas for cello and piano (or - much though it pains me to admit this - for piano and cello, to be more strictly accurate). It would be logical, for chronological reasons, to refer to the Bach suites as the Old Testament, the Beethoven as the New; but curiously, in musical terms, it is rather the other way around. The Bach suites can be seen as a musical portrait of the life of Christ (well - I see them that way, anyway); whereas the Beethoven sonatas are packed with thoroughly old-Testament-like fire, thunderbolts and mystical prophecy. There the analogy ends, however; both sets of masterpieces, sacred though they may be to us, are essentially human documents, full of humour, vulnerability, and boisterous joy. One salient feature of Beethoven's sonatas for piano and cello (which the Bach suites certainly do not offer us) is that they present a coherent biographical portrait of the composer. Listening to the cycle, we can hear the composer transforming in every way - in language, aspiration, and spirit. The early sonatas are creations of the fiery young virtuoso, revolutionising the concert platform. They rattle the cage of classicism, radically altering the world of chamber music - not just the cello sonata - in the process. Who before Beethoven would have thought to enter the genre with a sonata that is essentially a virtual concerto for two instruments (complete with written-out cadenza)? And then - even more startling - to follow this up with a second sonata that seems to take us into the world of opera, with all the dramatic violence that implies? Moving on to the third sonata, however, we encounter an absolutely different Beethoven: a master of classicism who at one stroke offers us perfection of form and of texture, achieving absolute equality between the two instruments - a feat that was never to be surpassed. And then, as we reach the fourth and fifth sonatas, written a mere seven years after the third, we are ushered into another sphere entirely: the mystical, radiant, uncharted world of late Beethoven.