Chapter 7: 7^th Chords

Here, again, is the family row of chords but now with a fourth note added. Note that I’ve moved to the key of B^b. Piano students often default to C, F or G major and the sooner you familiarize yourself with less familiar keys, the better. Brass players prefer playing in the flat keys!

These seven chords, each containing four notes, are the bread and butter of jazz. They are known as 7^ths and can be divided into four types.

1: Major 7 The chord symbol can vary but it is usually written as either Maj⁷ or as a triangle. For now I’m using the triangle.

2: Minor 7 The symbol may be min⁷ or m⁷. Here, I’m using m⁷.

3: Dominant 7 This chord is always represented by the number 7.

4: Minor 7 + b5 This usually appears as min7^(b5) or m7^(b5). I’ll be using the latter.

• This chord is also referred to as a half diminished, its symbol being a circle and forward slash: . Although you need to recognize this term and symbol, I prefer to use m^7(b5) or min^7(b5). My reasoning is that this chord usually functions as a minor II chord that leads to the V chord. This will make more sense when we move onto the subject of the II – V – I chord progression in chapter 14.

Let’s now examine each of these chords in more detail.

Major 7 chord

The easiest way to form a major 7 chord is to play the 1, 3, 5 and 7 of the major scale. Here are two examples:

G + B + D + F# = G major 7

D + F# + A + C# = D major 7

• The chord D⁶ comprises of 1 + 3 + 5 + 6 of the major scale but it’s usually described as a 6th, rather than a major 6th.

You learnt that a major triad is constructed from two intervals: a major 3^rd plus a minor 3^rd.

To create a major 7 chord, another major 3^rd interval is stacked on top of the triad.

Major 7 chord = major triad + major 3^rd interval. This produces the 4^th note.

1 + 3 + 5 + 7

Let’s take chord 1, B^b major 7: B^b + D + F + A

B^b - D: interval = major 3^rd

D - F: interval = minor 3^rd

F - A: interval = major 3^rd

As I’ve said, you can also think of a major 7 chord as the 1, 3, 5, and 7 of a major scale.

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EXERCISE Observe how this formula applies to chord 4: the Eb∆ (Ebmaj7).

Then build your own major 7 chords from any random note.

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Minor 7 chord

The minor 7 chord is built from a minor triad plus a minor 3^rd interval.

EXAMPLE Find Gm⁷

Start with the G minor triad: G + B^b + D

Then add a minor 3^rd interval above D.

Gm⁷ = G + B^b + D + F

Another route is to take the G major 7 chord and then flatten the 3 and 7.

Dominant 7 chord

The quickest way to find a dominant 7 chord is to play a major 7 chord, then flatten its 7^th note.

You can also play a major triad, and then add a minor 3^rd interval.

EXAMPLE Find E^b7

E^b major triad = E^b + G + B^b

Add minor 3^rd interval above B^b

E^b7 = E^b + G + B^b + D^b7

A common mistake

It is easy to confuse the two chords: major 7 and dominant 7.

Although they are both built from major triads, a major 7 chord adds a major 3rd interval whereas the dominant 7 adds a minor 3rd interval. Here are these two chords, side by side.

Note the use of a triangle for the major 7 chord. It can also be written as Emaj⁷.

Another way to identify the major 7 chord is by its top note, which is just a half step down from the octave above its root. In most other types of 7 chord, the top note is a whole step down from the octave.

Minor 7, flat 5 chord

Although this chord is sometimes referred to as half diminished, I prefer the above description, which speaks for itself: play a minor 7^th chord but flatten its 5^th.

As we will soon learn, this chord usually functions as a II that leads to its V and then resolves to its tonic (I) minor.

IIm⁷⁽⁵⁾ – V⁷ – Im⁷

Here is an example of the II – V – I sequence in A minor.

When we return to turnarounds, these 4-note 7^th chords will replace the triads.

Turnarounds will then lead us on to the sequence II – V – I: the very essence of jazz.

 

Meanwhile, I’m about to take you on a major diversion.