Chord Learning System
The Basics
In order to follow this chord learning system, you will need to at least know the seven chords in a major scale. The numbering in my system in based around that number system.
If you look at the chart below, you can use the following sequence: major, minor, minor, major, dominant (or seventh), minor and then major. These are the seven chords that make up the major scale.
The First Example
Just so you can follow what is going on, the first example is a simple 2-5-1 chord progression. This chord progression is very common in Jazz, but also found in other genres of music.
The basic principle is (2) Minor, (5) Dominant and then (1) Major.
Why 2-5-1? The three chords work well in music. For example, let's look at the key of C Major. We would start with the chord D minor, minor chords naturally have a little tension. The G7, dominant cords further increase tension, then finally the C Major releases the tension.
The alternative 2-5-1 progression
Time to get creative. Notice that the "1" chord is green. The "2" and "5" chords are yellow, meaning that they are the standard chords for the given key. You can easily observe that from the white chart at the top.
The meaning of the green chord
This means that the same note is to be played (e.g. C in the C major key) however a different chord type is used. The chord type to use is Minor in this case and this is show at the bottom of the green square.
Try playing this chord progression and listen to how different it sounds to the standard 2-5-1.
In the key of C Major, this chord progression would be Dmin7, G7, Cmin7. I have added 7ths to give it more depth. Do note that this can be applied to any key. For example the key of F major would be Gmin7, C7, Fmin7. This would sound a little more soulful than the key of C major.
Further Alternative Chords
Lets now look at changing two chords. Notice that the below chart has two green squares. The "2" chord is left as is, however both the "5" and "1" have become minor chords, therefore indicated as green.
In the key of C Major, the chord progression would now be Dmin7, Gmin7, Cmin7. You will hear that this has more of a jazzy feel to it.
I am using the key of C Major simply because it is easy to explain. However if I were to make a song I would have preference to the keys of F Major, Bb Major or Ab major.
It is also important to note that the melody may change slightly once you use green chords. Therefore any singer or accompanying instrument may need to pay attention to the new notes not present in the main key.
Borrowed Chords
In the below picture you will notice a blue square. The blue square represents a chord with key not in the given scale. This chord is located by counting half steps using the number displayed.
For example, if we were to play in the scale of C major. The final blue chord would be Bb major. The blue square shows <-2> so it means count backwards two half steps from C which gives you Bb.
The chord progression in the key of C Major would be Dmin, Cmaj, Bbmaj. Again this can be applied to any key. Try and experiment in other keys to see how they sound.
Mixing up the colours
The next example shows how both the green and blue squares can be used in the same chord progression.
In the key C of Major, the chord progression would be Cmaj, Dmaj, Dmin, Ebmaj.
The blue chord being the only chord in a different key.
Again try them in different keys but you will definitely notice that the progression sounds very different in other keys.
Bass Notes
The bass note of key in most cases is played as the root. For example the bass for the Cmaj chord would normally be "C". However it doesn't always have to be the root key. The below diagram shows that the 9th or sometimes even the 11th can be the bass key, if played an octave lower than the chord. Try it for a deeper sounding chord.