Oops! That looks like my longest article title yet! But it got you looking, right? Cool 🙂

Now that you know what the major scale diatonic triads are (check out my post on diatonic triads here), it’s time to expand the wee little triad to include it’s cooler, modern-sounding fourth note, that is to stack another note on top to make a Diatonic 7th chord.

Diatonic 7th Chords of the Major Scale

Here are the seven Diatonic 7th chords in the key of C Major:

Notice how just one additional note has given a slight twist to the chord qualities. The main quality of the chords are still there. With the exception of two of the chords, the major chords still retain their major quality sound and are still in the major chord family; the same goes with the minor chords. However, the 7th note has given each chord an extra bite, or a slightly more sophisticated quality, apart from contributing to a fuller, richer sound.

Now, the next important thing to look at are the chord symbols relative to each chord’s position (or chord degree)  in the scale:

Chord Degree	Chord	Chord Degree	Chord
I	Cmaj7	V	G7
II	Dmi7	VI	Ami7
III	Emi7	VII	Bmi7b5
IV	Fmaj7

The I and IV chords are both major 7th chords. The chord symbol is now represented by a capital letter along with ma7 or maj7.

The II, III and VI chords retain their minor chord quality to become minor 7th chords. The chord symbol is now represented by a capital letter along with mi7 or min7, sometimes you will also see this -7 (minus sign followed by the 7).

The two chords that take on different qualities are chords V and VII. Chord V is especially important to note because the added fourth tone has changed the major quality triad to one that is now called the dominant 7th chord. The chord symbol comprises simply the 7 next to the capital letter.

The Importance of the V7 Chord

The dominant 7th chord contains the 4th and 7th degrees of the major scale. If you take a look at the keyboard, you will notice that these two notes are part of two sets of white key halfstep intervals.  For example, G7 consists of the notes G-B-D-F — B is the 7th and F is the 4th. These two notes form the core structure of a dominant 7th chord and give it the “active” sound that calls for a resolution to a stable chord, which is usually chord I of the key.

Listen to the chord again, followed individually by the 7th and 4th notes and finally the 7th and 4th notes sounded together (forming a tritone interval).

In this case, G7 will move naturally and completely (or resolve) to C. Notice how and where each note moves from V7 (SO-TI-RE-FA) to I (DO-MI-SO-DO). Breaking the notes down to solfeg, you will see a very natural and organic movement in music, i.e. SO moves (up a perfect 4th or down a perfect 5th) to DO; TI resolves up a halfstep to DO; and FA resolves down a halfstep to MI.

In short, the V7 is a signpost to the key of a song or composition, since there is only one such chord quality in a major key. For example, if we see this chord progression, Gmi7-C7, there’s a great probability that we are in the key of F major; or G major, if it’s this progression: C-D7.

And finally, the last chord of the scale on the seventh degree, VII, is now a minor 7th with a flatted 5th. The chord symbol is a capital letter along with mi7b5, mi7(b5), min7b5, or min7(b5).

Traditionally, this chord is referred to as a half diminished. However, in pop and especially jazz music, we view this chord as having a minor chord quality rather than a diminished one.

So this wraps up all the seven diatonic 7th chords of the major scale. In the next post, I will show you how just by using these seventh chords, a simple song can be tweaked to sound more sophisticated. Meanwhile, learn and play them in all keys!