When these recordings were first issued, over a quarter of a century ago, Roger Fiske, Malcolm MacDonald and I all complained about the balance – the solo harpsichord concertos often being drowned by the strings (even though only single strings were used except in the D minor work played by Tachezi – who, disgracefully, is not credited on the front of the box) and the multiple concertos one long wearisome clatter, with their effect minimized by having all the harpsichords sounding from the same left channel. In ways that I don't pretend to understand, digital remastering has managed to make a few improvements: the tone of the instruments is still tinny, but at least in the two-harpsichord C major (though not in the two C minors) they can now be heard antiphonally. There are still some faulty balances – poor Tachezi only gets a proper chance to be heard when the strings are silent, and in the first two movements (but not the finale) of the Fourth-Brandenburg-based F major Concerto the harpsichord is far too faint in relation to the recorders – but elsewhere there again seems to have been some attempt to make things tolerable.
All the keyboard playing is, as you might expect, extremely efficient, and here and there we are offered some stylish embellishment; but the Leonhardt Consort so boot-facedly confines itself to one level of tone that dynamic contrasts are almost entirely confined to places where the texture changes (the Concentus Musicus shows more vitality and awareness of nuance); and no one seems to have noticed that the middle movement of the D major Concerto is marked sempre piano. Unfortunately Leonhardt often associates himself with this soulless sewing-machine style, and some of the performances (for example, of the A major) are chillingly austere. Some instability of pace in the outer movements of the F major may perhaps be attributable to splicing of different takes. Leonhardt's speeds occasionally seem uncomfortably fast, but on the other hand he takes the Andante of the G minor Concerto adagio.
You may have gathered by now that I didn't much enjoy this collection: nevertheless there are saving graces – the light, joyous finale of the D major work, the sprightly finale of the two-harpsichord C major, expressive playing by a solo violin of the melodic line of the D minor three-harpsichords' Siciliana, and the inclusion of the BWV1059 D minor work which makes a ghostly appearance in Cantata No. 35. By and large, however, this box is a must only for those who want all Bach's keyboard concertos together.'