Preparation of Chordal 7ths in Classical Harmony

Question

What is the proper practice for preparing chordal sevenths in dominant, diminished and other chords in classical 4-part harmony? In The Complete Musician (4th ed.) by Stephen Laitz, he states on page 199 that:

For V7, the approach to the dissonance (its preparation) can occur in different ways

What are the different ways that one can prepare the chordal 7th of the V7 chord, and are there different methods of doing so for other types of chord, such as the vii fully diminished or ii minor 7? If there are different methods, must the chordal seventh be resolved in a different manner?

Answer 1

Three patterns come to mind:

• degree ^5 moves to ^4 over a dominant chord, so the double chord root moves to the chord seventh, then resolves to ^3 - the third of the tonic chord, the basic idea is the dissonant seventh can be viewed as a passing tone not an essential chord tone.
• the degree that is the chord seventh is a chord tone of a simple triad in the previous chord - by necessity this is a common tone between the two chords, two common progressions: ii6 V7 and I ii6/5, the idea is the dissonant seventh is not reached by movement of the voice forming the seventh, it is held while the other voices move, then the dissonance resolves by move to a triadic chord tone in the next chord.
• the degree that is the chord seventh is held and becomes a chord tone (the third) in the next seventh chord, the idea is the dissonant seventh isn't resolved by moving the voice to a new tone, but the held tone become a consonance in the next chord by the movement of the other voices.

I used ties to highlight the held/common tones.

I think these patterns also illustrate typical seventh chord appearance in common practice. V7 and ii7 and their inversions are surely the most common seventh chords. Seventh chords in other roots are less common and often result from non-chord tone movement or sequential harmony.

Notice how in all cases some aspect of holding tones is used to smooth out the transition between dissonances and consonances.

Also, it seems worth noting how contrapuntal these patterns are. It's about movement of voices. "Classical" (common practice) harmony is really rooted in counterpoint. When the harmonic style shifts into a more purely chord based music - and the sense of contrapuntal voices is abandoned - you don't have the same sense of propriety about handling dissonant intervals.

Diminished seventh chords seem like a different case to me. Here are two examples from J.S. Bach...

Contrapuntally the raised ^7 moves up to the tonic and lowered ^6 moves down to the dominant. Of course the diminished seventh is the ^6 above the ^7 which is the root. In both cases the approach to the diminished seventh is by step. Functionally the diminished seventh chord is usually a dominant harmony built on a leading tone.

Answer 2

Assuming the 4th edition is the same as the 3rd at this point (though the page numbers are not quite the same) you have separated the first half of what the book says from the second half.

Taken together, they just mean "the 7th note of the chord can be preceded by anything, but must be followed by the note a semitone or tone lower" (in major or minor keys respectively).

He then claims that some preceding notes are more common (and "better" in some undefined sense) than others.

There are two self-consistent ways to write about common practice harmony. One is to observe what composers wrote historically, and attempt to extract general principles from it.

The other is to assume there is some Platonic musical ideal called "common practice harmony" and prescribe the rules for writing it.

The trouble with many books (including Laitz) is that they conflate the two things, and state dogma as if it were fact. It is quite reasonable for a student who wants to learn (as compared with one who wants to get a good grade in an exam) to question almost every pronouncement in a book like Laitz, and not find a convincing answer in the book itself - because there isn't any answer except "historically, composers wrote this more often than that."

In this specific case, it is easy enough to find common practice harmonic progressions which don't follow Laitz's dogma - for example where one dominant 7th chord resolves onto another one, in a progression like this:

Answer 3

Bach style SATB: You have to make concordant preparation of any seventh except the dominant seventh which does not have to be prepared. So the actual seventh note of the non-dominant seventh chord you intend to use, must be a concordant part of the previous chord. All the other notes can change but this note must be carried over into the seventh chord ( eg ii7), and then it resolves by step, usually downwards.

Answer 4

In using 7th chords, it is important to consider the movement of the scale degrees. 7 likes to lead to 8, 4 likes to move down to 3, etc. When resolving a 7th chord it is preferred that these types of movements are used. Pay attention to semi-tone movement in 7th chords that are not dominant-sevens so that you can see what notes from one chord might move most nicely to the next.

So, in preparation of the 7th chord, consider how to move a voice to notes in the 7th chord based on how they will resolve so that you will have the smoothest lines possible.

Some voices will dictate their path, like the melody. In the bass, inversions matter less in 7th chords because all four notes will be sung. There are fewer rules to keep in mind regarding bass notes, and voice doubling is irrelevant. However, it is a good idea to still watch for places where the interval between the bass and tenor is a P4 and the draw on the traditional usages of 6/4 chords in those instances.

Voice leading is the primary key. The smoother the line, the easier it is to convincingly go wherever you want, including borrowed chords, secondary sevenths, etc.

Answer 5

The basic rule is 'don't jump to or from a dissonance'. Approach and resolve it by step movement, or by no movement at all.

This, particularly the approach part, only applies to Bach-style SATB writing. Smooth part-writing is one thing. Dramatic leaps are also good - today or 400 years ago! Maybe more so TO a 7th than from it.