Lesson 9 - Root movement by 5th
Part I- Perfect authentic cadences
These are known as Perfect Authentic Cadences. They are Authentic cadences because they are V-I, and they are perfect because the root of the chords are in the bass. There are different types of cadences that will be discussed later.
Fig.1 Perfect authentic cadences in C Major.
Listen:
Fig.2 Lack of common tone in root movement by fifth.
Listen:
Notice that in the previous example there are common notes from chord to chord. This is good voice leading practices because the singers will be less likely to miss the note. Because they are singing the same tone from chord to chord.
In Fig.2, however, each new chord every voice has a new pitch to sing.
Fig.3 change of structure from chord to chord
Listen:
Changing the structure from Chord to chord is useful to avoid awkward leaps and bad voice leading. as demonstrated above in the first example, the structure is close in the first chord (V) and open in the second (I). the reverse is shown in the example on the right.
Part II - Plagal cadences
a plagal cadence is the subdominant (IV) chord leading to the tonic (I) chord
Fig.4 Plagal cadence in C Major
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Fig.5 Authentic cadence with plagal extension.
Listen:
As demonstrated in the example above, the plagal cadence is most commonly an extension to the authentic cadence. And is most commonly found at the end of a piece.
Part III - Half cadences
Fig.6 Half cadences
Listen:
A half cadence is a cadence that ends on the dominant (V) chord
