Diatonic chords②

Diatonic chords②

I tried to explain how to make diatonic chords and what the degree is in the previous chapter. I’ll explain something more advanced in this section.

【the degree name】
This is the C major diatonic chord that I used in the previous chapter.

Firstly, I’ll explain ‘The degree name’. Numbers like Ⅰ or Ⅴ are roman numerals. Ⅰ to Ⅶ correspond 1 to 7. At the C major diatonic chord, since C is the 1st degree (the root tone), it’s given the number Ⅰ. This would apply to the other numbers. For example, F is the 4th degree from C, so it’s Ⅳ. If you can’t understand this explanation about the degree, please go back to the previous chapter. Below is the image that I used before. 

Normally, to the right of the roman numerals assigned, the information of the chords like ‘△７’ or ‘m7’ would be added. And importantly, this degree name is shared in any major keys! So if you remember the mold of it, you can easily make diatonic chords in any keys(but you need to adjust the number of ‘#’ and ‘♭’. ). If the key is G and you put root tones in the mold in order from G, it’ll be like ‘G△7, Am7, Bm7, C△7, D7, Em7, Fm7♭7’.(To be precise, F would be F♯ but I’ll explain it later.)  Like this, if you remember the mold of the diatonic chord, it’s so beneficial for you to make diatonic chords easily in any key. So, I’ll use the degree name from now on.

【The functions of chords】
Each chord from diatonic chords has its own rule. It’s divided into ‘Tonic’ ‘Dominant’ ‘Subdominant’.

Tonic is the central chord of diatonic chords and has a stable sound that makes us comfortable. ‘Ⅰ△７’ ‘Ⅲm7’ ‘Ⅶm7’ have the function of a tonic. The reason why there are three chords is that those chords have a similar structure of notes and sound. So, for example, we can use Ⅲm7 as a substitute chord instead of using Ⅰ△７.

Dominant, which I mentioned before, has an unstable sound. The reason why it’s unstable and uncomfortable is that Ⅴ7 and Ⅶm7 have the sound of ‘augment 4th’ in their tone structure. Those unstable chords want to go to tonic chords to cope with tension. (This motion is called ‘Dominant motion’.)

‘Ⅳ△７’ and ‘Ⅱm7’ as subdominant have a mixed sound of tonic and subdominant. It’s less tense than dominant, but kind of tense and floating.

【Covering all types of diatonic chords】
Then, let’s make diatonic chords in all keys using the knowledge we have confirmed so far. The important thing is how many ‘#’ or ‘♭’ you need to add to each root tone. I’ll make it from the one having the least amount of ‘#’. 

・G major diatonic chord (#×1)

There would be the people who thought why # is added to F. But if you line up 7 notes in order from G, it’s going to be ‘GABCDEF’. And as I mentioned before, the interval of the major scale’s sound needs to be ‘W W H W W W H’. But the interval of ‘GABCDEF’ is ‘W W H W W H W’. So that’s why you need to add # to F so that you make it be like ‘W W H W W W H’. Make sure that # was added to the 7th degree. 

・D major diatonic chords (#×２）

In the D major diatonic chords, # is added to F and C. And the chord progression of C→G→D moves in 5th above intervals. Have you noticed? In the major diatonic chords, ‘the more the key moves in 5th above intervals from C, the more # would be added to the root tone of the 7th degree one by one. And the added # will be carried over even if the key moves in 5th above intervals.’ Then let’s see more. 
・A major diatonic chord (#×3)

In this key, # has been added to G (the 7th degree), and the # of F and C have been carried over. 

・E major diatonic chord (#×4)

・B major diatonic chord (#×5)

・F# major diatonic chord (#×6)

Note that as the key goes up from G to D to A to E to B to F#, the # was added to F to C to G to D to A to E in that order. Then, let’s see the key having ♭. 

・F major diatonic chord (♭×1)

♭ was added to B(the 4th degree).

・B♭ major diatonic chord (♭×2)

So far, we can see that ♭ was added to the 4th degree each time the key goes to the 4th degree higher(from C to F to B♭). In a # key, the key went to the 5th degree higher. On the other hand, in a ♭key, the key goes to the 4th degree higher.

・E♭ major diatonic chord (♭×3)

・A♭ major diatonic chord (♭×4)

・D♭ major diatonic chord (♭×5)

・G♭ major diatonic chord (♭×6)

So, in a ♭key, as the key goes up from G to D to A to E to B to F#, # was added from F to C to G to D to A to E in this order.

To summarize so far, it’ll be like below.
〇In a # key・・・# is added to the root tone of the 7th degree in order from F to C to G to D to A to E to B each time the key goes up the 5th degree higher.
〇In a ♭key・・・♭ is added to the root tone of the 4th degree in order from B to E to A to D to G to C each time the key goes up the 4th degree higher.

If you have a guitar or bass, it’s better to remember the above fingerboard image. The red line represents a 5th-degree progression and the blue line represents a 4th-degree progression.
For example, if you want to make ‘A major diatonic chord’, as A is the 3rd of the red line counting from C, you need to add # to ‘F C G’ in ‘FCGDAEB’. So firstly you should put root tones into the mold of diatonic chords, like ‘A△7 Bm7 Cm7 D△7 E7 Fm7 Gm7♭5’. After that, adding # to ‘F C G’, it’ll be like ‘A△7 Bm7 C#m7 D△7 E7 Fm7 Gm7♭5’.
In this way, if you know the mold of diatonic chords, how many # or ♭ you need to add, and a 5th and 4th progression, you can easily make all the diatonic chords.

I tried to explain ‘The degree name’ ‘The function of chords’ ‘How to make diatonic chords in all keys’. 

Thank you.