35. Major Sixth / Minor Sixth Chords (Part 1)

Getting Started with Sixth Chords

Up to last time we focused on avoid notes, but this time let's learn a new chord: the sixth chord, which adds a "6".

Sixth chords are another topic worth understanding together with avoid notes.
We'll cover how they relate next time, so for now, just learn the chords.

In particular, knowledge from the following lessons is assumed.
If you haven't read them or have forgotten, please refer to them as you go.

How the Major Sixth Chord Is Formed

Among four-note chords, the sixth chord is a little special.
First, let's check the sound of the major sixth.
The chord tones are played one by one, followed by the chord.

Depending on the person, it may sound old-fashioned, stylish, or calm and soft; it gives various impressions.

Let's listen to a major sixth chord after a major seventh chord.

There's only a one-note difference, but the impression changes quite a bit.

Notation of the Major Sixth Chord

The major sixth chord is written as follows.

Generally, most notations use just the "6" shown at the upper left,

• C major sixth = C6
• D major sixth = D6

and so on. (This course also uses just "6.")

Root Position of the Major Sixth Chord

Let's check C6 on the score and the piano roll.

Up to a point, it's a major triad.
Let's lay out the familiar intervals and check how it's built.

We can see that it is a major triad "R/M3rd/P5th (1/3/5)" with an "M6th" added.
Let's also check it with scale degrees.

To summarize, the root position of the major sixth chord is as follows.

• As intervals: "R M3rd P5th M6th"
• As scale degrees: "1 3 5 6"

Notation of the Minor Sixth Chord

Next, let's look at the minor sixth chord.
If you understand the major version, it isn't very difficult.

The minor sixth chord is written like this.

It is generally written "m6," and you'll also see "min6."
For its notes, the usual way of thinking tends to be "change the M6th (6) to an m6th (♭6)," but there's actually a pitfall here.
To give the answer first:

• As intervals: "R m3rd P5th M6th"
• As scale degrees: "1 ♭3 5 6"

In other words, the difference from major is that the 3rd is flattened, meaning the only difference is whether the triad part is major or minor (the M6th stays the same).

Let's also check the sound.

Since a tritone relationship is formed, some of you may feel tension.
There are in fact ways of using it that take advantage of the tritone.

If you were to change the M6th (6) to an m6th (♭6)...

It sounds really bad, doesn't it?
This is because it forms a half-step relationship with the P5th (5).
Also, this can be interpreted as a different chord, so think of it separately from m6.

Summary

Finally, let's summarize the major and minor sixth chords.

Sixth chords are easy to remember if you picture them as a major or minor triad with an M6th (6) added.

Next time, building on this lesson, we'll dig into content related to avoid notes.

Frequently Asked Questions

Q1. What is the difference between a major sixth chord and a major seventh chord?

A major sixth adds the 6th to a major triad (R, M3, P5, M6), while a major seventh adds the 7th (R, M3, P5, M7). There's only a one-note difference, but the sixth sounds softer and calmer.

Q2. Why shouldn't the 6th be flattened in a minor sixth chord?

The minor sixth gets its distinctive sound from the combination of "m3rd + M6th." Making it an m6th (♭6) creates a half-step relationship with the P5th, which sounds bad and functions as a different chord.

Q3. In what situations are sixth chords actually used in DTM?

The major sixth is used in classic styles and in soft passages of jazz and pop, while the minor sixth is used when you want to create tension or avoid avoid notes.