I. Intro to Chords

II. Triads and Inversions

III. Sus Chords

IV. Sixth Chords

V. Seventh Chords

VI. Extensions

VII. Add chords and Alterations

VIII. Bass and Polychords

IX. Modern and Chromatic Chords

 

 

Part II: Triads and Inversions

 

Weíll start with a more refined definition of a triad that was given earlier. Though a triad is built upon the tonic, mediant, and dominant degrees of a scale, this only defines a triad in as of itself. What about the specific sound and characteristics that makes up the different types of triads?

 

First, recall the two intervals, the major third and the minor third. All triads are built upon these two intervals. If you stack them on top of each other, you will get a total of four different combinations of triads.

 

Letís analyze C Major below:

 

[Piano showing tones highlighted...staff next to it indicating notes of the triad]

 

There are three tones that make up this chord. What is the interval between the first tone and the middle tone (the one and the three)? It is a major third. What about between the middle and the last tone (the three and the five). It is a minor third. You will notice the third is shared when making the comparison.

 

From this we can conclude that a Major chord is composed of two stacked intervals. It contains a major third on the bottom (hence the name ďmajor chordĒ) and a minor third on top.

 

Letís analyze a minor below:

 

[Piano showing tones highlighted...staff next to it indicating notes of the triad]

 

In the same manner as before, we can identify the major and minor intervals. Unsurprisingly, thereís a minor chord on the bottom and a major chord on top. A minor chord is composed of a minor third (bottom) and a major third (top).

 

We now have two very common chords in Western music...probably the most common in the early era (besides perfect fifth and fourths). However...we seem to have neglected 2 very important chords both of which were considered to be quite evil by the church for its horrid dissonance. Of course, not only is our own ear more in tune to this sound, but in the older music systems, the notes actually sounded different that they do on standard instruments today (see section on temperament), and actually much more dissonant as well.

 

The first chord we will look at is the diminished chord. Itís named this for two reasons. First of all, when we compare it to the next chord, we will notice that it sounds a lot ďsmallerĒ and more compact than it. The other reason has to do with the intervals itís composed of. A diminished chord is composed of a minor third on the bottom and a minor third on the top. This makes a fairly dissonant sound and is often used to create suspense or even make a very haunting sound.

 

In comparison to the minor chord, we find itís the same except the 5th tone of the chord was dropped by a half step. It was diminished in size.

 

The other chord is the augmented chord. An augmented chord is composed of 2 major third stacked on top of each other. In comparison to the major chord you can see that the fifth tone was raised a half step. It was augmented in size.

 

The table below summarizes the triads:

 

Type

Interval

Symbol

Example of Symbol

Major

M3, m3

M (optional)

C(M)

Minor

m3, M3

m

cm

Diminished

m3,m3

˚

Augmented

M3, M3

+

C+

 

Note 1: For Major, the ďMĒ symbol is usually omitted but you may see it occasionally.

 

Note 2: The letter of the major chord is usually capitalized (e.g. C Major). Likewise, the minor chord is usually uncapitalized. In this manner, since the diminished chord relates closer to the minor chord than the major chord, the same notation is used for the diminished as the minor chord. Major is closely related to augmented and therefore the augmented chord is usually capitalized to make it look similar to major. Also note that notation in general differs from place to place, but you will find that the triad notation is fairly similar.

 

Inversions simply build upon the concepts discussed in the previous section. A chord inversion is no more than a switching around of the tones of a chord.

 

For example, letís take C Major. C Major is composed of the tones C E and G. This is how it looks on the keyboard and staff:

 

[Picture showing keyboard and staff w/ C Major]

 

Now these tones can be rearranged in more than one way canít they? The C Major you know and are familiar with (CEG) is whatís called root position. Root position is any chord where the root note of the chord is at the root.

Letís take the C and move it to the top of the chord. We now have E G and C. Still the same chord...but different sound and look. We have just formed the first inversion of C Major.

 

[Picture showing keyboard and staff w/ C Major 1st inv.]

 

Now that we have E G and C, letís take the E and move it to the top. Now we have the chord G C and E. This is the second inversion of C Major. If you move the G to the top you are back with C Major in root position again.

 

[Picture showing keyboard and staff w/ C Major 2nd inv.]

 

Note that this does not mean the chord has a new root. The root is still C, but the bass note is the third or the fifth. Itís a precise distinction.

 

These chords are extremely useful for substitutions and have a number of usages in chord progressions. Their usage is also extensive in melodic compositions. Some of the most beautiful melodies can be created with just 3 tones.

 

Notation of the inversions used in chord progressions will be dealt with in the section on chord progressions (XII). Notation of inversions used in chord symbols will be dealt with in section IX.

 

There is another sort of ďinversionĒ you can make as well, but it is more appropriately titled as an alternative voicing. Once again we will work with C Major. You have the tones C E and G. How about switching the E and the G around? Notice, this is not really an inversion, itís still in root position but the third and fifth tones have been reversed. An inversion requires that the third or fifth of the triad becomes the new bass note.

 

So itís essentially just a different arrangement, or voicing of the tones. This will become much clearer when you begin to look at four-part writing in section X.

 

This section will be updated soon with information on interval inversions.