Rewriting Bach: Italian Concerto BWV 971, Presto m.112-121

March 03, 2017

Lately I've been writing some new music, and as part of that work, I've been taking a careful look at some pieces by Bach that I've never studied in depth. Over the last couple of days I've been analysing the Presto (third movement) from the Italian Concerto BWV 971.

Basics of Analysis

Four basic questions I try to answer are:

  1. How many ideas are there in this piece?
  2. How are the ideas organised?
  3. What is the harmonic scheme?
  4. How does the harmonic scheme relate to the organisation of the ideas?

Once these questions have been answered satisfactorily, I should have a pretty good grasp of what Bach did.

These questions help when trying to figure out how the ideas are organised.

I Wouldn't Change a Note!

Here is Glenn Gould playing the music which we'll be looking at. [N.b. This video was available as of April 11, 2020. If the link breaks, please notify me so I can fix it.]

When a piece of music sounds perfect the way it is, one is inclined to make remarks like "Not a single note should be changed!" But that doesn't teach anyone anything. The way to learn whether such a statement is true is to change some notes and see if it makes any difference.

I'm always on the lookout for places in a piece of music that could have been different. I like to look at these passages and try out alternatives to determine why what's there is there. One can learn a lot by doing this. In Bach's music, I've found consistently that the different possible versions are never as good as the version that's there. In other words, as far as I can tell, he always chose the best possibility. In Bach's Italian Concerto there is an intriguing passage at bars 112 and following that could have been different, but shouldn't be, and you'll see what I mean by taking a look at a possible alternative Bach didn't choose. Here it is the way he wrote it.

So we ask question 1: How many ideas are there here? The answer is two. A 1-bar motive (M) is being developed through imitation and sequence through most of the passage. Four bars from the main theme of the work (T1) appears in the second measure. For context, this passage comes basically in the middle of the entire work, after 8 bars of development of M (in its second appearance so far). It's the appearance of the theme here that interests me.

On to question 2: what is the harmonic plan? I also chose to look at this passage because it's the most harmonically ambiguous place in the entire work (again note that it appears almost exactly in the middle of the piece). My harmonic analysis is below.

In summary, we begin with a cadence in G Minor based on the motive (M), and then the Theme (T1) appears in B-Flat Major, followed directly by another cadence in G Minor, and then a sequence leading to a cadence in D Minor. The image below shows these key areas in a simplified way.

Places to Cut? or Insert

Take a close look at the two cadences in G Minor, and you'll notice they are very similar. In fact, the voiceleading is identical, and they both end up in exactly the same place.

Places like this are especially interesting for composers to study, because we can clearly see that Bach had an option to leave out some music here, but decided to put it in. So we see here a point in the music where we could, if we wanted to, make a "cut". Orchestral conductors do this sometimes, when they want to shorten a piece. They tell the orchestra to play up to point A, then skip over to point B and continue. This will only work when a conductor knows how to find places in the music that are similar enough that the music can continue smoothly and seem plausible, like this spot.

Look at this the other way around. As a composer, the similar cadences represent a place that music has been inserted, probably as an improvement of a first draft. Bach could have left out the appearance of the theme, and maybe he did at first. So let's see what we would have if Bach had never inserted the theme there. To recreate a fictional first draft, we simply remove the theme, and replace the second cadence with the first.

What is the result? Not surprisingly, it sounds perfectly fine, because the two cadences are so similar. The order in which the voices imitate one another (alto, bass, soprano) makes perfect sense. The impact of removing the theme here relates not only to the drama of this individual passage, but also to the larger form. It's quite possible that what we see above is what Bach wrote in his first draft, and he then added the appearance of the theme in B-Flat during a second draft, in order to make the passage more interesting and to improve the overall form. The similarity of the two cadences, the logic of the imitation in the abridged passage above, and most importantly the unexpectedness of the key of B-Flat Major all lead me to suggest this idea as a real possibility.

In an Alternate Universe …

Now let's consider another, less likely possibility. Let's say we're Bach, and the first draft is above, with no statement of the theme. Let's pretend we've decided that the piece will be better if the theme appears here, and we're going to insert it after the G Minor cadence. The question we must answer is: in what key it should appear? The fact that Bach answered this question with "B-Flat Major" is what interests us, and we can find out why he chose that key by choosing a different key for our alternative-universe second draft, and comparing the result.

We have a cadence in G Minor. So why not state the theme in G-Minor? Sounds logical enough. Stating the theme in G Minor will certainly work here. The theme begins with a descending octave leap, and we have a G on the downbeat of 113 to work with. Good. Note that we don't need to write a second cadence in G Minor since the theme does that for us. Sounds auspicious. Let's try it, and see what happens. To change the theme from B-Flat Major to G Minor, we can simply transpose what Bach wrote down a third and change some accidentals (and if that seems like an indication to you that something might be wrong with this idea, you get bonus points). Here is what we get.

Hm, it works, but it isn't altogether convincing. Why? Let's fix some obvious things first. When we look at other statements of the main theme in this work in Minor key areas, we see that Bach always used the ascending form of Minor, with the raised 6th and 7th, so we should also do that here, because otherwise it sounds weak and wrong. The repeated G in the left hand at the entrance of T1 is clumsy; we can leave out the downbeat. If you would have already fixed these things during your transposition step, you also earned bonus points. Let's circle the problem spots.

So here it is with these couple of problems fixed (marked in blue).

It still sounds a bit unrewarding. Is this just because we expect Bach's version and ours is different? Doesn't a statement in G Minor make sense here? What's the problem? The key areas are more straightforward than Bach's version. We have only G Minor and D Minor.

If you thought that transposing down a third a few bars of what Bach actually wrote isn't likely to sound quite right in context, you were correct. We see that the result is unfortunately a bit dull. The reason is because we end up repeating the same notes at the at the same pitch level. We begin with a cadence that has a D half note in it, and then we ascend a scale again to the same D and repeat that D. D for Dull. In our version, the appearance of the theme doesn't bring much new to light. It lacks excitement. It may even bring Disappointment.

Bach Wins

At this point you should be shouting "Please bring Back Bach's original!" and you would be right. But let's list a few reasons why his version is so much better in comparison to what we did. Here is what Bach's statement in B-Flat does that our statement in G Minor doesn't do. It's quite simple.

We could note other things that make Bach's version better, like the pitch change from A to A-flat, then back to A, the change from Minor to Major, the ambiguity of G Minor to E-Flat Major to B-Flat Major. All those things are good observations.

So let's return to is Bach's original with a new appreciation for what he did in this passage, and possibly even how he did it, imagining that he inserted it in a second draft and covered his tracks by writing a second cadence in G Minor after the statement of the theme.

I hope this example might help someone else who is considering making changes to a draft of a piece. Seeing what Bach did here should encourage all composers to consider options wisely and make the most of opportunities. What seems like a logical choice is definitely not always the best choice, and often an inferior choice results from asking the wrong question — a question that is too simple-minded. Diversity of harmony, which notes we hear in what register — these are extremely important things that need to be considered when answering a question like "in which key should the theme appear here?" and thinking about all those things together should lead one to more musical conclusions.

Why not spend the next 15 minutes of your life listening to all three movements? Here is a performance of the work by Alexander Gavrylyuk. [Please notify me if this link breaks]

Thanks for tuning in, and I hope to see you next time.

Regards,
Aaron

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