Re: Passages that bother me BWV 552a (St. Anne, Prelude)

July 22, 2023

This is a short followup to our previous episode in the series "Passages that bother me", where I thoroughly scrutinised a questionable transition found in the great St. Anne Prelude which opens Bach's Clavierübung III, published 1739. We begin by citing the passage in question as Bach wrote it. The transition in question is between bars 175 and 176.

After publishing my investigations, which contained many possible approaches meant to possibly "improve" the above transition, I received a remarkable alternative which hadn't occurred to me, written by the esteemed composer Stéphane Delplace. A brief exchange of observations led to the following "final version".

The core idea of this alternative is to replace the B-Flat triad in first inversion with a D minor triad in root position. It's difficult to convey just how much wisdom is contained within this surprisingly simple idea.

Recall that a B-flat triad is the most distant diatonic relation to be found in C-Minor, and this fact is in large part responsible for giving the transition an awkward effect. When we replace this harmony with D-minor 7th chord, the majority of the awkwardness is removed in one stroke, since a very distant harmonic relation is replaced with a very close one. When the fifth is present, the chord is an altered harmony in the key of C minor, since the 6th degree must be raised from A-flat to A, but Bach's voice-leading suggests that the fifth shouldn't immediately appear; rather, it should "sneak in" almost unnoticeably. This note, A, then acts as a leading tone to B-flat, so that the voice-leading is finally as smooth as it should be. Because the C is now held as a common tone, the similar motion is decreased just enough that it no longer draws any undue attention to itself.

As an added benefit, this sonority on D minor contains not only a 7th, but also a 9th, namely the small 9th E-flat above the root D. Here is where a deep knowledge of Bach's harmonic language helps to understand why using this specific chord as the solution might just qualify as a stroke of genius! Because this specific chord, a minor triad with a minor 7th and minor 9th, turns out to be one of the most important aspects of Bach's harmonic language. I almost want to say something like "the best kept secret" of his harmonic language, because it seems few people have taken notice of Bach's consistent use of this specific harmony throughout his work. Precisely this sonority occurs as a ninth chord in the major mode, on the third degree, iii9. In minor, it appears here as an altered ii9, where the perfect 5th in the chord is the raised 6th of the minor mode, which is exactly what we see here in the above solution.

In fact, Stéphane Delplace has written a treatise on this very subject, this sonority and the special role it plays in Bach's music, which may be one of the most important treatises on harmony in the modern age. To everyone who wants to understand Bach's harmony, please go now and read this treatise. It is available directly from Delplace's website both in the original French, and in an English translation (which I had the honour of helping with).

III V § I C A (MUSICA, a treatise on harmony by Stéphane Delplace)

As a final note, I also came up with my own version using this same approach, to address a few things about the above solution which still bothered me. First, I found that the B-flat appearing already on beat 2 in the alto was too early, and the arrival should instead be saved for the descent of the soprano. Second, the full triad in three sustained parts on beat 3 seemed to stray unnecessarily from the original which sounds only the single note B-flat at that point. Lastly, the chords in the right hand require an awkward "hopping" motion if they are to be played by one hand, which I found counter to Bach's normal fluid style (although it is easy enough to play the passage by taking the second alto with the left hand, which is how I played it for the above recording). My version resolves these issues by introducing the fifth (A) as a quarter note on the second beat and resolving it on beat 3, resolving the second soprano to a unison with the first soprano, and dropping out the alto on beat four. The result is as follows.

Upon comparing these, I have to admit that, despite my objections, Delplace's version sounds smoother. The reason is that it contains no distracting elements, whereas the accented A in my version makes the ii9 stand out. Therefore I consider Delplace's version to be better. Which do you prefer? As always, I'm curious to hear what you think. Whatever you do, be sure to get the treatise! It has the potential to help you appreciate Bach's music on a new level, and radically change the way you think about harmony in your own work.

Peace,
Aaron