Here are two recent issues of Book 1 of Bach's 48 or, more properly Das Wohltemperierte Clavier. Recently issued, certainly, although Ton Koopman recorded his set in 1982; Glen Wilson's recording, on the other hand, was made last year. The two approaches are clearly differentiated both interpretatively and by reason of strongly contrasting instrumental sonority. Koopman plays a modern copy of a Ruckers harpsichord, Glen Wilson another modelled on the fine instrument by Christian Zell in the Hamburg museum of arts and trades. The character of both instruments is faithfully captured in the recordings but in general I prefer the more spacious acoustic and greater radiance of the Teldec set. The Erato acoustic is a shade dry and the Ruckers harpsichord consequently less bright and more brittle-sounding than the Zell.
Koopman and Wilson are both accomplished musicians with fine keyboard techniques. Their tempos average out similarly, though each player on occasion hits on a speed which differs considerably from that of the other. Sometimes I found Koopman's rhythms jerky and unsettling; the C major Fugue is a case m point. But his articulation and phrasing are clear, though to my ears often lacking the poetry of Gustav Leonhardt (Deutsche Harmonia Mundi/BMG) or Kenneth Gilbert (Archiv Produktion) for example. The Prelude in C sharp major comes over drily with too much emphasis placed on its pedagogical purpose, though I should add that Koopman is not assisted by the recording acoustic. Wilson brings more brilliance to the piece but makes it all sound a bit of a scramble and is inclined to push an already dangerously brisk tempo.
Neither player makes as much sense of the music as Leonhardt, who uses a lute stop—an effective choice for the movement—or Davitt Moroney (Harmonia Mundi) who, alone among his colleagues, succeeds in making the left-hand quavers sing out. This piece is not a mere study and by taking a more leisurely view of it, and by the application of carefully controlled rhythmic unevenness Moroney allows us to revel in the poetry of the music and not just the mechanism of it. Wilson finds a great deal more to say in several of the other pieces such as the C sharp minor Prelude whose arioso character is beautifully captured. Likewise, Wilson is articulate and expressive in its five-voice Fugue with its three subjects. This is music well worth pondering over and savouring to the full and Wilson allows us to do that.
Koopman favours a somewhat faster tempo, and though he permits himself a degree of rhythmic freedom, I found his approach unsettling. His account is articulate but the arioso element is only partly brought to life; on the other hand, I liked Koopman's tautly controlled Fugue. Similarly Koopman brings character to the Fugue in D major in the manner of the dotted measures of a French overture. He is also admirably clear and rhythmic in the D major and D minor Preludes, in which Bach earlier had provided his eldest son Wilhelm Friedemann with contrasting right-hand finger studies. Wilson, too, gives a sparkling account of these pieces though not entirely without a hint of rhythmic monotony in the D major, where the left-hand quavers sound too insistent.
As you will have realized by now each of these new sets has its virtues and its disappointments. In general Koopman has a greater feeling for delicacy in expression and is the more indulgent of the two in matter of ornamentation. Sometimes I welcome that, at others I find it unwarranted and irritating. His playing of the transparently-textured two-voiced Prelude and Fugue in F sharp major is delightful. Wilson's approach sometimes, though by no means always, sounds more overtly virtuosic than Koopman's but he does tend to spoil pieces by rushing through them; the Prelude in G major is an instance of this, where all is sound and fury signifying nothing. Koopman scores over him here with a more leisurely tempo and clearer defined articulation.
A difficult decision. There is no shortage of performances of the 48 on CD. Both of these are worth considering and which of them you choose will in the end be largely a matter of taste. My own preferences lie with Kenneth Gilbert and Davitt Moroney but these are available only as four-CD sets containing Books 1 and 2. Bob van Asperen (EMI), Ton Koopman and Glen Wilson, on the other hand are being issued in two separate albums and their respective second volumes cannot be far away. Leonhardt's fine recording is already available in two separate releases, but should you prefer to hear the 48 on the piano there are complete versions by Glenn Gould (CBS/Sony Classical) Sviatoslav Richter (Eurodisc/BMG) and Friedrich Gulda (Philips). Two older EMI reissues are also well worth getting to know: Wanda Landowska on (harpsichord), recorded c. 1950 and Edwin Fischer (piano) recorded during the 1930s.'