First inversion chords are most useful for voice leading. See how the Bass has stepwise motion in both of these examples from the first inversion ii chord to the V chord. The left side has the ii chord in root position, whereas the left side has the ii chord in first inversion and it eliminates the leap from the ii to the V chord.
Fig.1 first inversion chords
Listen:
Here, the bass also has a second from the first inversion ii to the second inversion I Chord.
Fig.2 First inversion chord leading to second inversion chord
At cadence points, it is common to find a specific chord inserted into the circle of fifths progression. This is the Cadential six-four chord. Remember that the six four means a second inversion chord? When writing the progression, the bass voice would not have the need to change pitches as the fifth of the I chord is the same note as the root of the V chord.
The progression would look like this:
As shown here, the second inversion tonic chord can be inserted between the ii and the V chord to elongate the progression.
In this first iteration, the common tones are in the bass and tenor voices while the soprano and alto move from the six-four chord to the V chord.
In each of the examples, the common tones are bracketed.
Fig.1 Cadential six-four chord in D Major First iteration
Listen:
Here in the second iteration, the Soprano and bass have the common tones, while the other two voices move.
Fig.2 Cadential six-four chord in D Major Second iteration
Listen:
Finally, you can see in this last iteration, the bass is the only voice to have the common tone, the G. Which is the 5th of the I chord, making the chord in second inversion (six-four) then in the next chord, it stays on the G which is the root of the V chord in C.
Fig.3 Cadential six-four chord in D Major Third iteration
Listen:
Lastly, here is an entire chord progression with the cadential six-four chord inserted into the appropriate spot.
The final category of root movement is that of a third.
This gives opportunity for many common tones among chords separated by a third. For example:
C - E - G
A - C - E
This is true for ANY two chords where the root is a third apart. This means that when voicing the chords, two voices can hold the same pitches while the other two voices change around them.
Fig.1 two examples of root movement by third in C Major
Listen:
In the first example, the I and vi chord are separated by a third. In the second example, the I chord and the iii chord are separated by the third.
Part II - The subtonic triad
This triad is most often found in the minor chord progression in the iteration: i-VII-III-VI-ii°-V-i
Here it is in c minor:
Part I - Progressions
Chord Progressions that use root movement by second:
I-ii-V-I I-IV-V-I i-iv-V-i
In each of these progressions, the underlined chords have roots that are a second apart.
Root movement by 2nd is one of the more important types of progressions because it creates the best indicator of key signature. The I-ii-V-I progression. This will come in handy later when we discuss key change techniques.
You can see that the I and the ii chords have a root separated by a second.
Fig.1 Root movement by second I-ii-V-I
Listen:
Part II - Deceptive cadences
A deceptive cadence is that which ends on the VI chord. The I chord and the VI chords have two common tones e.g. C - E - G (I in the key of C)
A - C - E (vi in the key of C)
Thus, when writing a progression, the vi chord can be a substitute for the I Chord.
Fig.2 Root movement by second I-IV-V-vi
Listen:
This last example is simply root movement by second, not examples of deceptive cadences.
In context, the word "voice" does not necessarily mean that the music is to be sung. It simply means that there are more than one melodic strand, each of which are called a "voice." They fit together to make up pat of a larger texture.The process of creating a multi-voice texture is called part writing.
Part I-Introduction to part writing.
In general, there are four voices to write for: Soprano, Alto, Tenor, and Bass.
In general, the order goes like this: Soprano on top, Alto directly below Soprano, Tenor directly below Alto, and Bass on bottom.
Fig.1 part writing voices
Listen:
Part II-Open and close structure
Close structure, the notes are arranged so that there is not more than a fifth between voices.
Fig.2 Close structure
Listen:
Open structure- where there is more than a fifth between two or more voices.
The Xs indicate chord tones that have been skipped.
Fig.3 Open structure
Listen:
Part III- Voice Ranges.
In general, voices should stay within these ranges. Of course there are exceptions.
Also voices should not cross meaning for example. the Alto is higher than the soprano. The ranges do overlap quite a bit, however they should not cross.
Fig.4 Vocal ranges
Part IV-Part writing practices.
Parallel intervals of a fifth and octave are frowned upon when part writing. Here is an example of parallel octaves in part writing
Fig.5 Parallel octaves
Listen:
When writing repeated chords, it is good practice to alternate between close and open structure.
