Harmonic functions
	by Ivan Barasnevicius

Hello guys ! I hope all stuff we studied last months in this column had been truly useful for the musical life of each one of you ! To continue our course, we will study now a subject that is reputed as some of the most essential points inside tonal music: The harmonic functions, where’as there are three main functions: tonic, dominant and sub-dominant.

        Tonic function

The tonic function brings us a resolution, rest sensation. The existing chords in first degree of the major and minor context have the tonic function. These chords can be used in a musical piece’s conclusion, which does not necessarily mean that it is not possible that certain musical pieces or sections within the same could not be concluded in the first degree.

Dominant function

The dominant function comes up with a sensation of tension. There are two degrees, in major or minor contexts, which can be considered as dominants: V and VII (in minor context we will consider the V of the harmonic minor scale). Some musicians believe the half-diminished chord (or diminished, in harmonic minor context) on the VII are the V with the root replaced by 9M or 9m. In all cases, the most important element of the dominant chord is the tritone interval between the 3M and the 7m of the V degree, or the tritone interval between the root and the 5° of the VII chord, which means that the dominant chord can also have other tensions included (like 13M, 13m, 9M or 9m, obviously in the V degree), but the tritone and his prospect of resolution are essential for the dominant chord.

        Subdominant function

The subdominant chords give the sensation of being far from the tonic cited previously. There are two degrees, in major or minor contexts that can work as subdominant: II and IV. Some musicians consider the subdominant as a preparation to the dominant chord. There are others, such as Arnold Schoenberg, that consider the subdominant as a extension of the harmonic progression. In major context, the VII will be called relative minor, while the III will be called anti-relative. This relation will be reserved in minor context, where the III will be called relative major, and the VI eill be called anti-relative.

HARMONIC PROGRESSIONS

The tonal music discourse generally is all based in the use of harmonic progressions. There are some progressions that are commonly used by composers of diferent kinds of popular or classical music. Jazz musicians, as an example, usually study lots of tonal progressions, and its harmonic and improvising possibilities. That happens because a great part of the jazz repertoire is built with this progressions, therefore, it is very important for the musicians who want to play this kind of music to know how to build solos and chords over this progressions.

 Cadences in major mode

We will now study some of the most important chord progressions used by composers. It is possible to realize the scales that should be used for improvising are already indicated.

Authentic cadences in major mode

The cadence is called “authentic” when it has the V-I movement, as you can see in the example 1. If the melody rests in the root of the tonic chord, this progression will be called “perfect authentic cadence”.

Example 1: Authentic cadence (V-I)

The two following cadences (examples 2 and 3) are commonly used in tonal music, althought the example 2 is easier to be found. Take a look at the subdominant-dominant-tonic chord change. This progressions are called “authentics” (refering to the V-I change) and can be also called “perfect authentics” if the melody rests in the root of the tonic degree. The subdominant chord can also be considered an extension (or a preparation) of the dominant, as we cited previously in this column.

Example 2: Authentic cadence (II-V-I)

Example 3: Authentic cadence (IV-V-I)

        Deceptive (or interrupted) cadences

The deceptive (or interrupted) cadence happens when the chord progression frustrates the V-I cadence, as you can see in the examples 4 and 5 (the deceptive cadence doesn´t necessarily need to be targeted to the VI, however, this is the most common progression, so it will be used as an example here).

Example 4: Deceptive (or interrupted) cadence (II-V-VI)

Example 5: Deceptive (or interrupted) cadence (IV-V-VI)

         Plagal cadences in major mode

The progression called plagal happens when the subdominant goes to the tonic, that could be IV or II degree, as you can see in the examples 6 and 7.

Example 6: Plagal cadence (IV-I)

Example 7: Plagal cadence (II-I)

         Half cadences in major mode

Now we can talk about a cadence that is very useful in tonal music, which is called half cadence. The half cadence happens when you can find the dominant chord in the end of the musical phrase, what means that it is a suspended cadence, because its resolution will happen in the beginning of the next musical phrase.

        Other useful cadences:

I – VI – II – V – I
I – VI – IV – V – I
III – VI – II – V – I
III – VI – IV – V – I

 Minor mode cadences

To build cadences in minor tones, we will use the elements founded in the three different minor context chords, but not in a sistematic way (specially in concern to improvisation) just like we did before, but trying to make the example cited the most useful as possible. We also should mention that there are a lot of different possibilities for improvising in this situation. The cadence names will be the same used for major mode cadences. Just remember that, in a minor context, we can find some different possibilities for each degree. For example, in A minor, the I degree could be Am7 or Am7M. However, with the following cadences, you can have a better idea of which chords and scales are used in each situation.

         Cadences in minor mode

Jazz musicians, in this kind of cadence, commonly uses the altered scale over the dominant chord (the altered scale is formed by: F,2m,2+,3M,4+,6m and 7m – all this intervals are possible in the cited chord), as you can see in the example 9. In the II-V-I and IV-V-I cadences of the examples 10 and 11 it´s also possible to use the alteres scale in the V chords.

Example 8: Authentic cadence (V-I)

Example 9: Authentic cadence (V-I)

Example 10: Authentic cadence (II-V-I)

Example 11: Authentic cadence (IV-V-I)

          Deceptive (or interrupted) cadences in minor mode

In major situations, the deceptive (or interrupted) cadences in minor mode happens when the chords sequence frustrates the V-I resolution, as we can see in the examples 12 and 13. As we cited about major mode situations, not necessarily the deceptive cadence must be target to the VI, however, this is the most useful sequence.

Exemplo 12: Deceptive (or interrupted) cadence (II-V-VI)

Exemplo 13: Deceptive (or interrupted) cadence (II-V-VI)

Plagal cadences in minor mode

As it has been told previously, talking about major mode cadences, the plagal cadence in minor mode happens when the subdominant goes to the tonic, but it doesn´t matter if it is IV or II, as we can see in the examples 14 and 15.

Example 14: Plagal cadence (IV-I)

Example 15: Plagal cadence (II-I)

        Half cadences in minor mode

As we cited before about minor mode, the half cadence is also very useful in minor situations. Again, this procedure happens when we have the dominant chord in the end of the musical phrase, which means that it is a suspended cadence with its resolution in the beginning of the next phrase.

Next months, we will study other relevant aspects relationed to harmonic cadences as well as some other significant subjects. Any doubt or suggestions? Send an e-mail to: ivan@venegasmusic.com ! Hugs !