Harmonising the major scale, what is it? Why do we need to know it? And how do we apply this knowledge? If these questions interest you, then stick around and you will learn all you need to know about harmonising the major scale!
In this article we will be going over one of the most important parts of music theory, harmonising the major scale.
Understanding how this functions is key to understanding how chord progressions work as well as lots of theoretical concepts in the future. The topics we are covering are as follows:
What Does It Mean To Harmonise?
To first fully understand what we are talking about when we bring up the subject of harmonising the major scale, we need to understand what it means to harmonise something.
Harmonisation simply put is when you are contrasting notes together to create a harmony or sound. This can be applied to melodies, chords and even just a few intervals. Often whenever we are listening to music it’s a combination of chords and melody creating harmonies, the harmonisation is the end result of all the notes combined.
Harmonising in Thirds Or Stacking Thirds
When we think of chords, we don’t often think about what goes into making them what they are. Chords are formed by taking any scale, (in this case the major scale) and counting by three notes at a time starting from the first note.
In Example 1:
It shows that we start with the root (the first note of the scale) then we can go up the scale by three more notes to add the next note in the harmonisation, the next note is another three notes from that note.
When we are counting, we include the note we are on as the first one, not going from 0 to 1 but including the first note. Doing this creates the first chord of the major scale using tertiary harmony (stacking thirds), you can go further and add more thirds to gain your extensions but to keep things simple we will keep it to 3 notes. AKA 3-part harmony.
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Why Harmonise The Major Scale?
The reason why we harmonise the major scale is that each degree of the major scale has its relevant chord to it. If we did the process of harmonising in thirds or stacking thirds to all of the degrees of the major scale, we get this sequence in Example 2:
The sequence as outlined in Example 2 is Major, minor, minor, Major, Major, minor, diminished.
These relevant chords to each scale degree define how we understand chord progressions entirely.
To fully understand the sounds of the harmonised major scale we need to stack one more third from the perfect 5th note to make 4 part harmony chords.
When we stack thirds to 4 note chords, we start using what are known as 7th chords. The sequence as shown in Example 3 spells out Major7th, minor7th, minor7th, major7th, dom7th, minor7th and minor7th flat 5.
Example 3:
The reason why we needed to take it to 4 note chords is that it helps define the chords a bit more than triads.
I believe that the most important takeaway from this harmonisation is what happens on the 5th degree of the major scale I.e., the dominant chord as this always indicates how it wants to resolve to the first chord which helps determining the key signature.
Roman Numerals And Their Relationship To The Major Scale
Each scale degree of the major scale, along with the chord has a corresponding roman numeral designated to it.
In Example 4, you can see which roman numeral belongs to which scale degree.
Example 4:
As you can see its very easy to understand, the capitalisation of the roman numeral means they are major chords. And the lower-case roman numerals mean they are minor chords. We often refer to each scale degree and roman numeral as numbers which can be shorthand for communicating to other musicians what chords can be within a chord progression. It also can be used for easy modulation (key changing) by stating the roman numerals as they are a constant no matter what key you use.
For example, a common chord progression is a I IV and V. If we take this from the key of G to find what chords happen in the key of G, we have to understand that in the key of G we have an F#. So, because the first note is G, G is our I chord or the first chord.
To get the next chord we can count up 4 notes from the G major scale which gives us the note C of which we build a major chord again because of the previous work we have done of harmonising the major scale. To get our next chord we count up 5 notes from G and we get the note D we can either do the major chord or dominant depending on how many notes you would like to add.
This process is how we determine which chord is used within which key from harmonising the major scale.
Common Chord Progressions Using The Harmonised Major Scale
Here are some common chord progressions that are used from harmonising the major scale. We can use short hand via using roman numerals to communicate chord progressions really quickly.
As mentioned above a common chord progression used in Rock and blues music. Is the 1 4 5 or I – IV -V.
Another common example is a chord progression that’s used a lot in pop music and has its own roots in classical music and that’s the I-V-vi-iii-IV-I-IV-V often cited to stem from Pachelbel's Canon.
Lastly here is our last example of another common chord progression 2-5-1-6 or ii-V-I- vi.
There are many, many variations on chord progressions using numbers and roman numerals as there are tonnes of songs out there but hopefully by reading this article it gives you understanding of what it means when we use roman numerals or numbers in this way.
Excellent explanation! Thanks!