A Structural Examination of Tonality, Vocabulary, Texture,
Sonorities, and Time Organization in Western Art Music



Chapter 24. B is for BASS LINES

Chapter 23. A is for ANALYSIS
Chapter 25. C is for COUNTERPOINT
Chapter 26. D is for DIVERSITY
Chapter 27. E is for EMBELLISHMENT
Chapter 28. F is for FINISHING


The bass line is the single most important reflection of the chorale tune; only if the bass works well with the soprano can the entire chorale work. The bass line must fulfill three crucial requirements:

  1. The bass line must be an independent and individual line.

    It must be able to stand alone as a melody, with a good contour and linear rationale, as described in the Species Counterpoint unit. Essentially this means the following:

  2. The bass line must work contrapuntally with the chorale tune.

    Every note in the bass line at this stage will ultimately become a chord tone. Certain precedures that must be observed:

  3. The bass line must support the structure of the chorale tune.

    The two basic principles of support are

    1. Prolongations are supported by prolongations
    2. Cadences are supported by cadences

    The most solid support a bass can give is root support. Therefore, implied tonic prolongations in the soprano should be supported by a prolongation of ^1 in the bass. This primarily means that ^1 is the focus of the bass line, and is usually accomplished by beginning on ^1, moving away from it, and then returning back to it. Three simple ways to do this (among other possibilities):

    Prolongations are always completed before arriving to the cadence.

    Each cadence formula found in the soprano receives a specific kind of support from the bass:

    The information above describes the process for writing the simplest, most obvious, bass lines. When the analysis of a soprano line can be done in several different ways, the bass line is altered to support each version.

    Obviously, if the melody modulates, so must the bass line, requiring the proper accidentals and the shift of support to reflect the new key.


Once the bass line is completed, an implied harmony can be projected from the combination of the bass and soprano. The bass note gives the most information, but the soprano clarifies. Sometimes there are several possibilities which can work, but each projected harmony must work within the standard models of structural analysis. In other words, each chord must have an identifiable function to prolong, connect, or cadence.


Frequently chorale melodies have cadence structures in which the penultimate note is a half-note or two repeated quarter-notes. If the bass is also a half-note at this point, the harmonic rhythm will slow down at a crucial place (right before the cadence). It is imperative to keep the motion going; this is best achieved with a stepwise bass motion under the half note (see the example below), which then creates a change of harmony. Be careful to keep the cadential structure intact.

Bach frequently solves this problem with an accented dissonance, often a suspension, in one of the upper voices. When this happens, the suspension must be indicated as part of the Roman numeral analysis since it has a significant effect on the pace of harmonic change. This suspension will inevitably occur over a dominant area, and will look somewhat like the analysis of the cadential 6/4 to dominant motion.

Students should use the stepwise change of bass solution in their writing, and leave the use of the accented dissonance to Bach.


Below is the same melody analyzed in Chapter 23 with good bass support:


The processes described above to write a bass line are greatly simplified. The truth is much more complicated. In further analysis work, you will be exposed to some examples of good representations of this process but also to some examples which are not as straight-forward. It is these exceptions which make the chorale an artful act of composition.



The following is the same series of analysis projects from the previous chapter. Write a simple bass line to the melodies, project the implied harmony, then compare to the one Bach wrote to accomplish the same task. The odd numbers give answers (after you work on them) and the even numbers are for you to do on your own.

Bass line 1: Nun ruhen alle Walder
Bass line 2: O Ewigkeit, du Donnerwort
Bass line 3: Wie schoen leuchtet der Morgenstern
Bass line 4: Jesu, meine Freude
Bass line 5: Vater unser im Himmelreich
Bass line 6: Wo soll ich fliehen hin


Write a good bass line to the soprano melody of the final project (Chapter 28. F is for FINISHING), using the analysis completed in the previous chapter. Complete this with a computer notation program, distribute the measures proportionally in four systems, and submit for a grade.

Links to chapters in this unit:
Chapter 23. A is for ANALYSIS
Chapter 25. C is for COUNTERPOINT
Chapter 26. D is for DIVERSITY
Chapter 27. E is for EMBELLISHMENT
Chapter 28. F is for FINISHING

Link to previous unit: CHROMATIC PROCEDURES I: Moving from the Global Key

Link to next unit: LARGER PERSPECTIVES

Copyright 2008-2009 by Phillip Magnuson.

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