For this section, a prior knowledge of intervals and chord triads is necessary.
In jazz styles, it is rare to see a chord that is simply a triad. This is because, simply, a triad is very boring. By extending the chord to the seventh (or further) it adds extra colour to the chord, and extra framework for improvisation to take place. Below is a C major triad:
The notes currently in this chord are C, E and G. However if we add the major seventh (B natural) we end up with a 4 note chord – C major 7. Hear the difference between these two chords below. The first chord played is a C major triad, the second chord is a C major 7.
Notice with the previous example I very clearly noted that we were adding a major seventh to the top of the chord. So what happens if we add a minor seventh? Introducing the C dominant seventh chord (also referred to as C dominant, or C7).
This chord is the same as the major seven chord except it has a Bb on the top. This chord is referred to as dominant as it occurs naturally on the chord built on the 5th note of a major scale. Lets explain that.
Think for a second about an F major scale – F G A Bb C D E
We can see clearly that the 5th note (or dominant in classical harmony) is a C, so we will build a chord based on C. To build a chord, look at the scale and take a note, leave a note and repeat till you have all the notes of your chord. We want to build a 4 note chord.
Lets rewrite the scale from C for convenience and take the notes of our chord – C D E F G A Bb. Doing this we end up with the C dominant seven chord! Hear the difference between a major triad and a dominant 7 chord below:
It is important to understand that a dominant chord comes from the 5th note of a major scale as this is the driving force of most forms of music. This is due to the fact that strongest possible resolution in music is when the chord falls by a perfect 5th. A resolution is when the music builds tension and then relaxes again to the key centre. Many people like to think of the following analogy:
We have the chord progression |Cmaj7|G7 |Cmaj7|. When the I chord (C major 7) is sounding, the music is sweet and relaxed. It is home. When it moves to the V chord (G7), it is as far away from home as it can get, right in the middle of the scale and builds tension that it can only release by going back home again.
There is one further basic chord type – the minor 7th chord. This is created by simply taking a minor chord and adding the minor 7th to the top.
C Eb G Bb. Hear the minor 7 chord below:
Here are some tips for working out chords:
- If in doubt, draw a simple piano keyboard to help you work out the problem or print the one in the Reference Sheet section of the Resource heading and keep it on your desk or in your study folder. There is also a table of all the common chords and the notes they contain (I will link both at the bottom of this page).
- I find it helps to work backwards when working out what the seventh of the chord is – rather than counting up 7 notes count down from the root. A major 7 is one note below the root and the minor is a whole tone below.
- A minor 3rd is three semitones above the root.
- It can sometimes be easier to work out the major 7 chord first then apply alterations as necessary. A major seven chord occurs naturally with the key signature of the root note. For example, if you required to work out a chord based on E, write the scale as per the key signature. E F# G# A B C# D#. If we use the process of taking a note and skipping a note we get E G# B D#. We know that this is a major seven chord as we used the E major key signature. To make this a dominant chord simply flatten the 7th to D natural so we now have E G# B D. To make it a minor 7 chord also flatten the 3rd, to end up with E G B D.
- The description of the chord (whether it is major, minor, dominant, etc.) is said to be its quality.