A Guide to the Relationship Between Chords and Scales
1. Regular Triads in Major Scales ⚖️
When we think about chords it is easy to think of them as their own entity, thinking… a “C major chord is just a C major chord and this is the notes C, E and G”. However, in music this isn’t entirely how they function. Although we can certainly find chords on a piano independent of any other information, chords are better understand in context and by how the chord relate to each other and to the piece of music you are playing.
This is why it is important to understand the types of chords that exist and the types of chords we expect to see when playing a piece of music.
Firstly a TRIAD is a 3 note chord and this forms the basis of any chord in music. There are 4 types of triads that you can come across:
- a major triad
- a minor triad
- a diminished triad
- an augmented triad
Firstly, we can learn how to construct these types of triads without any context by understanding how the notes in the triads relate to each other:
- A major triad is constructed by leaving a gap of 3 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note.
- A minor triad is constructed by leaving a gap of 2 individual notes between the first two chord notes and a gap of 3 individual notes between the second and third note.
- A diminished triad is constructed by leaving a gap of 2 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note.
- An augmented triad is constructed by leaving a gap of 3 individual notes between the first two chord notes and a gap of 3 individual notes between the second and third note.
However, this information only provides us a way of constructing the varying types of chords and doesn’t help us understand which chords work well together or which chords might be used together in a piece of music.
For this, we need to understand which chords appear in any given scale (or key) that you might come across. In a regular major scale we can form triads starting on each note in the scale, to form the triads that will appear with in a given scale, we can simply find alternate notes in the scale to form the triad.
E.g. C major scale - C D E F G A B
The triads that are used within this scale are therefore:
Chord 1 - C E G (C major triad)
Chord 2 - D F A (D minor triad)
Chord 3 - E G B (E minor triad)
Chord 4 - F A C (F major triad)
Chord 5 - G B D (G major triad)
Chord 6 - A C E (A minor triad)
Chord 7 - B D F (B diminished triad)
Although using a C major scale results in these 7 triads, the types of triads that we find can be applied to any major scale. For example; chord 1 will always be a major triad, chord 2 will always be a minor triad and chord 7 will always be a diminished triad regardless of the major scale we use!
E.g. B major scale - B C# D# E F# G# A#
Chord 1 - B D# F# (B major triad)
Chord 2 - C# E G# (C# minor triad)
Chord 3 - D# F# A# (D# minor triad)
Chord 4 - E G# B (E major triad)
Chord 5 - F# A# C# (F# major triad)
Chord 6 - G# B D# (G# minor triad)
Chord 7 - A# C# E (A# diminished triad)
This means that it is often best to think of chords as numbers in the scale because this can give us more information about the type of chords we expect to see and how it relates to the scale and how it relates to the other chords in the scale. If we have chord 5 in a scale we know that this is going to be a major chord and if this is followed by chord 6 then we will be moving to a minor chord. Thinking of chords in this way also allows us to play songs and pieces using multiple different scales.
If we have a chord progression of I - vi - ii - V, then using the scale of C major we would be using the chords C major, A minor, D minor and G major. However, the same progression could be played using another scale. In B major, this progression would be B major, G# minor, C# minor and F# major. Both of these chord progressions would have the same qualities of sound and relate to each other in exactly the same way.
2. 7th Chords in Major Scales 🎷
We can take this one step further by adding 7ths to each of the triads. There are 5 types of 7th chords that are available to us in music.
- a major 7th
- a minor 7th
- a dominant 7th
- a half diminished 7th
- a diminished 7th
Similar to regular triads we COULD think about each type of 7th as a chord independent of any context. A 7th chord consists of 4 notes rather than the 3 notes that occur in regular triads.
- A major 7th chord is constructed by leaving a gap of 3 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note and a gap of 3 individual notes between the third and fourth note.
- A minor 7th chord is constructed by leaving a gap of 2 individual notes between the first two chord notes and a gap of 3 individual notes between the second and third note and a gap of 2 individual notes between the third and fourth note.
- A dominant 7th triad is constructed by leaving a gap of 3 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note and a gap of 2 individual notes between the third and fourth note.
- A half diminished 7th chord is constructed by leaving a gap of 2 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note and a gap of 3 individual notes between the third and fourth note.
- A diminished 7th chord is constructed by leaving a gap of 2 individual notes between the first two chord notes and a gap of 2 individual notes between the second and third note and a gap of 2 individual notes between the third and fourth note.
Using these types of chords in isolation can make it difficult to understand and can make choosing chords that sound nice together even more difficult. However, fortunately we can also think of 7th chords as they relate to the scale (or key) of the piece of music we are playing (or writing).
To form 7th chords that work in a scale we can simply play the triads by finding alternating notes in a scale and add 1 extra alternate note to these triads.
E.g. C major scale - C D E F G A B
Chord 1 - C E G B (C major 7th chord)
Chord 2 - D F A C (D minor 7th chord)
Chord 3 - E G B D (E minor 7th chord)
Chord 4 - F A C E (F major 7th chord)
Chord 5 - G B D F (G dominant 7th chord)
Chord 6 - A C E G (A minor 7th chord)
Chord 7 - B D F A (B half diminished 7th chord)
These are the types of 7th available to us in a major scale. In music the word “dominant” means note 5 or chord 5 and this is why the type of 7th that falls on note 5 of the scale is called a “dominant 7th”. If we find the types of 7th used in any major scale we will find that they are the same types of 7th chords each time. For example, chord 1 will always be a major 7th chord, chord 6 will always be a minor 7th chord and chord 5 will always be a dominant 7th chord.
E.g. B major scale - B C# D# E F# G# A#
Chord 1 - B D# F# A# (B major 7th chord)
Chord 2 - C# E G# B (C# minor 7th chord)
Chord 3 - D# F# A# C# (D# minor 7th chord)
Chord 4 - E G# B D# (E major 7th chord)
Chord 5 - F# A# C# E (F# dominant 7th chord)
Chord 6 - G# B D# F# (G# minor 7th chord)
Chord 7 - A# C# E G# (A# half diminished 7th chord)
Now we are able to use chord progressions that use regular triads and 7th chords and understand how they relate to the scale and the other chords. We can also take a chord progression and play it using any other of major scales understanding the types of chords we are going to be playing.
If we have a chord progression of I - IV7 - ii7 - V7, using the scale of C major we would have a C major triad, F major 7th chord, D minor 7th chord and a G dominant 7th chord. The same progression in B major would result in the same chord types, B major triad, E major 7th chord, C# minor 7th chord and F# dominant 7th chord.
3. 3 For 1 Learning 🏷️
Initially chords and chord types might feel overwhelming and like there are too many chords types to remember! However, there are actually only 12 of each type of each triad (one starting on each key) and we can build upon these to make the 7th chords. This means that the same types of chords appear in lots of different scales. For example a C major triad (C E G) can be found as chord 1 in the scale of C major, but it can also be found as chord 4 in a G major scale and chord 5 in an F major scale.
Learning chords by learning how they relate to scales is not only the quickest and best way of being able to practically use chords to play and write music, but it will also teach you the scales and which chords naturally work well together and why…giving you a much fuller understanding of music! You will also be able to learn the various chord types as you use them in a much more fun way and you will understand the different qualities of sound in each type of chord.
Matthew Cawood
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