Other piano recordings of Das wohltemperierte Clavier have come and gone; one remembers Cole, Tureck and Gould with considerably varying degrees of affection. The operative word is, however, 'gone' and we are left with none with which to compare Gulda's; Gilbert is arguably the best of the available harpsichord versions (Archiv Produktion). Bach's 'Clavier' was not specified, maybe not even in his own mind, but it could not have been a modern piano; we can thus only take the piano for what it is, an entirely different instrument from those Bach knew, and consider how it serves the music as we understand it.
The piano's greater clarity (versus the harpsichord) serves it well in the fast-moving passage-work of some of the Preludes, e.g. those of I/14 and I/21, even though Gulda's tempos are higher than Gilbert's—50 per cent higher in the former case. Under the same conditions however the piano's blander sound makes Preludes II/11 and II/21 sound more like technical exercises than they should. Staccato is one device that helps to keep contrapuntal lines differentiated and it also adds life. However, the piano separates notes more cleanly than the more resonant harpsichord and too readily exaggerates the effect, as Gould demonstrated (often disturbingly) and Gulda often does here. He has it about right in Prelude I/6 but overdoes it irritatingly in Prelude I/24; in other sundry places the effect suggests a one-legged tap-dancer or the transmission of B, D, H and S in morse code. Legato is the piano's strong suit and Gulda plays it most effectively, not least in some of the Fugues, e.g. I/24 and II/8, both taken very slowly and with calm, sad dignity; in others, however, Gulda's legato, coupled with slow tempos, encourages him to daydream, e.g. I/18 and II/2. Perhaps the most extreme case is that of Prelude I/8, in which his tempo is little more than half that of Gilbert (Gould was both slow and eccentric), turgid and denaturing. Conversely, neither Gulda nor Gilbert takes Prelude II/20 slowly enough to convey the pathos of the Affekt implicit in the falling chromatic lines; Gulda takes the associated Fugue XII/20 at a leisurely tempo (quaver = 88 versus Gilbert's 108), making it sound prissy and humourless. In general, the piano's capacity for legato and its clarity at high speed do seem to tempt Gulda to some extremes, some of which work well—others do not.
Gulda is not conservative in his approach to ornamentation; sometimes he follows the score, sometimes he doesn't, and often he adds his own embellishments. In some cases they sit happily but in others they seem surplus to establishment, as in Prelude II/14 and Fugues I/8 and I/6, the last trivialized in the process. In the repeats in Prelude II/12 he even ornaments numerous appoggiatura notes! Appoggiaturas are frequently too short, e.g. in Prelude II/19, bar 19, and inverted mordents too often start by dead-centring the main note on the beat—particularly noticeable and irritating when the tempo is slow, as in Fugue I/18. Unsurprisingly, Gilbert does no such things, and, though he adds less, his extra embellishment is always apt. The over-dotting in Gulda's Prelude II/16 sounds aggressively spiky but he does render the four-quaver group in Prelude II/V (first appearing in bar 2) evenly, as the slurs suggest, whereas Gilbert makes them inegale, displacing the middle-voice notes in bar 18 to secure consistency, which seems questionable.
If the above (and other, unrecorded) reservations seem to loom large, let me hasten to say that this is a very worthwhile set (more to those who regard the harpsichord as a piano with a bad cold than to others) with some very fine playing; even though they do not always produce felicitous results, the thought and affection that have gone into these performances are obvious. Gulda has a fine technique, particularly evident in the separation of teh contrapuntal lines in the Fugues, and only occasionally is his touch too hard for comfort. The recording is first-class. The 'earliest' sets of the WTC spread over six LPs (Gould managed it on four by a variety of means, not wholly desirable) and Gulda (as also Gilbert) requires, thanks to technical advancement, only five, and without sacrificing repeats. That the same music is offered on only four CDs, with durations of 67'35 to 71'28, represents a commendable effort to pass on to the customer the benefit the medium affords.'