#10 - Prolongation of the Bass Line
FOR Advanced Students
In the previous two blog posts I introduced the concept of prolongation over the first four measures of Bach’s famous Prelude in C Major from the Well Tempered Clavier, and expanded upon that concept for measures 5-19 in the Treble Clef. In this blog post, I will discuss the prolongation in the Bass line between measures 1-19.
To summarize the past two blog posts, we were able to see that the entire melodic progression in the treble clef between measures 1-19 is simply a full octave descent from the opening arpeggiation of measure 1. In other words, the arpeggiation in measure 19 is exactly the same as the one in measure 1, only a full octave lower. And so, this concludes our first unit of meaning.
When we as performers take to play this, and are aware of this octave descent - and therefore treat measure 19 as an important point of arrival - it changes our performance in such a way that it highlights the harmonic and melodic tension that is built into this mechanism of the octave descent, and therefore tightens our performance, as opposed to us just playing the notes on the page without being aware of their nuance, hierarchy and overall compositorial mechanism.
Having reviewed this, let’s examine the melodic progression in the bass between measures 1-19.
New York: G. Schirmer, 1893. Plate 11015
LESSON 1
Suspensions as a Prolongating Tool
1) Measure 5 keeps the same middle C in the Bass clef as in measure 4 to serve as a bridge from the first unit of meaning (m. 1-4) to the next (m. 5-19).
2) Since measures 1 and 4 are identical, we are essentially still on the same note in measure 5 of the Bass clef as the one that opened the piece.
3) Take a quick glance at measure 19, and see that the Bass note is still C, only this time a full octave below.
4) If you examine the rest of the notes in measure 19 (C, E, G, C, E), you will see they are identical to those in measure 1, only an octave lower.
5) Now that we are aware of the bookends that create a full octave descent, let’s look into what is in between those bookends.
6) The mechanism of suspension (consonance turning into dissonance) is used widely here. For example, in measures 5-6: while the C in the bass is a consonance for measure 5, it stays put (therefore, being suspended) to turn into a dissonance in measure 6 that needs to then be resolved, which it does in measure 7.
7) The same technique is used in measures 7-8, 11-12, 13-14, and 15-16 as well. Not only that it throws fuel into the engine to keep it moving, it also delays the descent, therefore creating even more tension. In the treble clef the engine was the 5th motif; in the bass it is the suspension.
LESSON 2
The 5th Motif, The Engine
1) So far, the Bass has been moving in a downward stepwise motion. This intensifies the tension by using the suspension mechanism and allows for a close and slow movement, akin to crawling. To vary, as well as to create some sort of a meaningful punctuation, Bach uses the 5th motif here as well to solidify the Half Cadence.
2) For example, take measures 9-11. The note in the bass in measure 9 is A, while the note in measure 11 is G. They are scalar neighbors, and the goal is to get from one to another, by way of delay. This is done, then, by the motif of the 5th.
3) And so, the note that we find in the Bass of measure 10 is D, a 5th lower than A. This is followed by G in measure 11, a 4th up from D, which is the inverse of the 5th. If you are unfamiliar with the idea of inverse intervals, please see the explanation in the “Advanced Practice” section below.
4) This same mechanism is used again in measures 16-18, where between the D in measure 16 and the C in measure 18, we find G – a 5th lower than D – before the 4th up resolves our journey back to C.
5) Notice that this is only done when approaching cadences – the motion is otherwise stepwise, and consists of suspensions.
Lesson 3
Bird’s Eye Look
1) Having gone through all measures from 1-19, we see two important things: A) The full octave descent, and; B) the two engines of suspension and the 5th motif that are being used in order to create this tension, and delay the movement by stretching the resolution further and further.
2) Notice that measures 1-4 were very straightforward, and that the prolongation was only four measures long. Here, we are already dealing with a significantly longer prolongation of 15 measures – almost 4 times as long!
3) The goal, in both cases, was the same: to start at the tonic, and end at the tonic. The difference is the length of our trip.
4) Upon continuing to analyze this wonderful piece, you will see how the length of the prolongation intensifies and being stretched to even longer periods.
Advanced Practice
Explanation about inverse relationship between intervals: Let’s take the notes C and G for example, C being 1 and G being five away from it (C, D, E, F, G). If the G goes down to C, then it is five notes away. If, however, it goes up to C, it is only 4 notes away (G, A, B, C). Therefore, the inverse of the 5th is the 4th
Inverse intervals tend to reveal a deeper layer of the architecture of a composition if they are used in a consistent manner, which is indeed the case here.
On a purely technical level, inverse intervals will always amount to 9. Meaning, the 4th is the inverse of the 5th (5+4=9); the 3rd is the inverse of the 6th (6+3=9); and the 2nd is the inverse of the 7th (7+2=9). To examine this, take any two notes and see how far away they are from one another in both directions - you will see that the sum of both numbers will amount to 9.
A Final Thought
There are a few ideas here that weren’t discussed in this post, but they are also very telling.
1) Notice that m. 19 resolves as an Imperfect Authentic Cadence (a tonic cadence with the soprano not being the 1st scale degree). Beyond the idea of completing a full octave descent, this is done in order to signal that our journey is not over yet! It will be over once we reach a Perfect Authentic Cadence (a tonic cadence with the tonic in the soprano as well). Up until then, the tension and suspense is mounting! Bach prepared some cadential trickery for us that will be a joy to behold!
2) We discussed the importance of the 5th as a motif in this piece, and a common practice in Schenkerian Analysis is to highlight the inverse of such motifs - in this case, the 4th. These fourths, present in the bass clef on measures 10-11 (D to G) and 18-19 (G to C), lead each in turn to a cadence: measures 10-11 to a Half Cadence, and measures 18-19 to an Imperfect Authentic Cadence.
3) Finally, notice the intervals between the notes on measures 5, 7, 13 and 15: fourths and fifths!
Conclusion
All of these measures, 1-19, have only one goal in mind – to prolong E in the treble clef! Why is that?
We previously discussed the two melodic lines in Schenkarian Analysis - the 3-line and the 5-line. Since this piece uses the 3-line (begins with E in the treble clef), it needs to make the descent to 1 as slow as possible.
The bass line is using the same technique to support the melodic line, but it is not the melodic line on its own - meaning, they are not of the same importance. It is akin to a family going on a vacation: they need to get there by using their car, but the car on its own is likely not the crux of the vacation. The bass line is the car that allows the vacation to happen; the melodic line is the essence of the journey, the meaningful experiences of the vacation.
And so, the primary goal of this section is to keep the 3rd of the melodic line in place in order to extend our journey. It takes us on a really fascinating trip that leaves home and returns back home, which makes us feel different by the time we return as a result of all the experiences we went through.
In the next blog post we will explore the next unit of meaning of this piece.