When Gunar Letzbor plays the opening chord of the First Sonata, he stretches it out so far that you could be forgiven for reaching for your booklet-notes to double-check whether you’ve got the right disc. That degree of manipulation and manner is a theme of Letzbor’s slow movements, and can dramatically interfere with the plain and simple emphasis of Bach’s distinct melodic lines. The fast movements have more harmonic drive and are much more enjoyable to listen to as a result, although there is a strong sense in this recording that one step back from the music might have injected an equitability into the discussion of Bach’s arguments that would conversely have made them more powerful. There is undoubtedly a greater sense of calmness in the performance of Rüdiger Lotter, from which it benefits greatly, although, equally, there can be a sense there that it pervades the Chaconne a little too much, where the player is slightly more passive a partner to the music than he ought to be.

The acoustics of Letzbor’s performance are its principal players: their flatness, and the extreme closeness of the recording, adds an intimacy to these most intimate of pieces. Given Bach’s own particularly close relationship with them, it is hard to imagine that he would not have approved. The sound feels raw and authentic, although the downside of recording it quite so close is that, unless there is a vast array of variation in tone, it can become relentless without at least a small amount of reverberation to mitigate and support it. Lotter’s chosen acoustic, on the other hand, could not be more different: the wide-open space of the Himmelfahrtskirche in Munich brings his performance a ghost-like quality that works equally well in its own way.

Neither recording displays any of the intonation issues that dog a vast proportion of recordings of these pieces but at the same time neither really retains a sense of the spirit of the dance that they should have, or displays the kind of sinuous expansion needed to propel the listener through the scale of the music’s harmonic growth, leaving recordings that are fundamentally muscular feeling strangely without bite.