To record Bach’s “48” complete – 96 intensely-crafted miniatures spanning nearly five hours – is an immense undertaking. Ian Holtham arranges the movements not in the traditional chronology – Book I (1722) then Book II (1742) – but by key. Each key pair has Book I before Book II, save at the half-way point (F minor) and the end (B minor), where he puts the lighter Book II before the profound Book I. His unique ordering exposes many correspondences and relations between the pairs not heard before.

Holtham plays Bach insightfully, adding personal ornamentation, tonal shading and articulation. His fugue voicing is always crystal clear, while his delicacy in some of the most archaic fugal types is almost subdued for such grandeur.Rapid pieces are given virtuosic renditions, difficult problems are gracefully solved. In Book II he makes sense of often rambling structures with clever contrasts of articulation and tonal shading: the G Sharp Major Prelude – the only one with f/p marks, almost unrecognisable as Bach – is exquisitely given, bound to the vast triple fugue that follows, a total contrast of introverted chromaticism. Closing with the Book I B Minor Fugue, its subject the first 12-tone row in music, Holtham takes the Largo mark literally, and plays with a grandeur and freedom of tempo and dynamic contrast that wonderfully captures its sublimity and make a fitting close to a vast and impressive anthology.