J. S. Bach’s seven Toccatas (BWV910-916) remain a rather niche and under-explored part of his output for keyboard, perhaps mainly appreciated by connoisseurs or serious devotees of the composer, and oddly still probably more favoured by pianists than harpsichordists on the evidence of available recordings. Mahan Esfahani’s version of the complete set, for all its many accomplishments, seems to be addressed to those converted few rather than setting out to win new admirers.

The Toccatas are comparatively early pieces, apparently composed around the 1710s (though no original manuscripts exist) and therefore contemporary with the Toccatas written for organ which are paired with Fugues. These Toccatas for keyboard comprise a different sort of structure, however, and are only loosely categorised under that term for want of any better one. They are more expansive works than their organ counterparts, superficially in one movement, but consisting of several discrete and contrasting sections, some of which are strictly-written Fugues.

They open with—and sometimes reprise—the sort of finger-stretching flourishes which characterise the first half of those organ compositions (the D-major opens with an echo of the organ Prelude BWV532 in the same key) but they also feature an array of other stylistic techniques.

The impression from Esfahani’s readings is sometimes that he does not quite know how to forge a given Toccata into a convincing unity, despite his manifest enthusiasm for them (as expressed in his cogent reflections in the booklet) and the painstaking effort he has exerted in creating fresh editions from the extant sources to reconcile contradictions and errors in a practical, artistic fashion. Some sections feel more like studies in counterpoint, as Bach toys obsessively with particular figures or motifs in predictable sequential patterns, or fugal subjects are less pliable than those he achieved elsewhere. In an attempt to import more dramatic interest and variety, Esfahani often makes long pauses between sections, even when the score seems to warrant more or less the opposite. To take an obvious instance, the cascade of notes which opens the C minor Toccata lands on a low C which ought to act as the springboard for the immediately succeeding section, in order to generate structural tension and flow, rather than functioning as the point of rest for the flourish that precedes it. As a result, the structure becomes disconnected, and the opening flourishes, in particular, are fashioned as ends in themselves.

Esfahani rightly draws contrasts in tempo, register, and character between one section and the next to bring these works to life. For example, the Fugues often proceed with serious, driven purpose, even when witty as in the F sharp minor or the ebulliently oscillating instance in 6/16 meter in the D-major; the smoother, more plastic articulation of the E-minor’s opening section is distinguished intriguingly from the more spindly and sprung execution of the others’ introductory sequences. Within sections, the listener can depend upon Esfahani to ensure that alignment between the polyphonic parts of the texture is tight and secure; rhythms are precise when necessary, contrasting with the more rhapsodic, freer unwinding of the genuine Toccata-like passages; and voice-leading in Fugues is persuasive.

The harpsichord Esfahani plays was recently created by the workshop of Jukka Ollikka in Prague, and is based on surviving examples by Michael Mietke (Bob van Asperen and Menno van Delft also use instruments of the same provenance in their Toccata recordings). Not only does the keyboard create a generally resonant timbre overall, it presupposes from its models the addition of an extra soundboard for the lowest (sixteen-foot) stop, which can provide impressive weight and heft for the bass lines, and particularly for the forceful pedal notes that underlie the mercurial passages, mimicking the effect of an organ.

These are unquestionably astute and imaginative readings in which Esfahani achieves an easefulness (as compared with van Asperen’s slightly livelier if less-thoughtful accounts) and confidence that belie the strained face of an eighteenth-century character head by Franz Xaver Messerschmidt which inexplicably adorns this release’s cover. That assuredness does not quite carry over the joins and seams within each Toccata, however, and goes against their having a more appealing and likeable effect in these versions, which is surely crucial in making the best possible case for these often dry and inscrutable compositions.