So, you know how there are 6 7th chords most commonly used in music and 12 that are theoretically possible? Well, I have played around with these 7th chords, and I can say for sure that I have a specific ordering of them as far as consonance and dissonance goes. And here is that ordering from most to least consonant:
Now, my theory on the consonance and dissonance of seventh chords relies on tendency tones. There is one seventh chord that might seem out of order here, but, I will get to it in due time. Now first, I have to define a tendency tone, otherwise everybody will disagree with my theory. A tendency tone is a note that wants to resolve by half step.
Starting with the minor seventh:
None of these notes want to resolve by half step, so none of them are tendency tones. Thus the minor seventh is the most consonant seventh chord. This is in fact, the only seventh chord that has no tendency tones. The rest of them have at least 1 tendency tone. The minor seventh provides an ambient, relaxing quality.
Major seventh:
Now, this seventh chord has a single tendency tone, the seventh itself. The seventh wants to resolve to the root and so the chord as a whole wants to resolve to the major chord it is based off of.
Dominant seventh:
Out of all the seventh chords that exist, this one is the most common. It has 2 tendency tones as opposed to the 1 tendency tone of the major seventh. The seventh is still a tendency tone, because now it wants to resolve to the third of the next chord. The third is also a tendency tone, wanting to resolve to the root of the next chord. So, the dominant seventh is more dissonant than the major seventh.
Minor major seventh:
This is the major outlier, not just in rarity, but also in the tendency tone to dissonance correspondence. Technically speaking, this chord only has 1 tendency tone, just like the major seventh. And like the major seventh, the tendency tone is the seventh. But this chord is way more dissonant than the major seventh. That probably has to do with the minor chord base. So, just as CM7 wants to resolve to C major, CmM7 wants to resolve to C minor.
Half diminished seventh:
Now, this chord has 2 tendency tones just like the dominant seventh. The root is a tendency tone and wants to resolve to the new root. The third isn't a tendency tone, but the fifth is a tendency tone with the fifth wanting to resolve to the new third.
Diminished seventh:
This chord takes seventh chord dissonance and tendency tones to the max. Because of the 2 overlapping tritones, a single diminished seventh chord is very dissonant, even more so when it moves to another diminished seventh. And, every single note in the diminished seventh is a tendency tone, because every note wants to move by half step.
So, what do you think of my tendency tone theory on the consonance and dissonance of seventh chords? Do you agree with my seventh chord ordering from most consonant to most dissonant?
- Minor seventh
- Major seventh
- Dominant seventh
- Minor major seventh
- Half diminished seventh
- Diminished seventh
Now, my theory on the consonance and dissonance of seventh chords relies on tendency tones. There is one seventh chord that might seem out of order here, but, I will get to it in due time. Now first, I have to define a tendency tone, otherwise everybody will disagree with my theory. A tendency tone is a note that wants to resolve by half step.
Starting with the minor seventh:
None of these notes want to resolve by half step, so none of them are tendency tones. Thus the minor seventh is the most consonant seventh chord. This is in fact, the only seventh chord that has no tendency tones. The rest of them have at least 1 tendency tone. The minor seventh provides an ambient, relaxing quality.
Major seventh:
Now, this seventh chord has a single tendency tone, the seventh itself. The seventh wants to resolve to the root and so the chord as a whole wants to resolve to the major chord it is based off of.
Dominant seventh:
Out of all the seventh chords that exist, this one is the most common. It has 2 tendency tones as opposed to the 1 tendency tone of the major seventh. The seventh is still a tendency tone, because now it wants to resolve to the third of the next chord. The third is also a tendency tone, wanting to resolve to the root of the next chord. So, the dominant seventh is more dissonant than the major seventh.
Minor major seventh:
This is the major outlier, not just in rarity, but also in the tendency tone to dissonance correspondence. Technically speaking, this chord only has 1 tendency tone, just like the major seventh. And like the major seventh, the tendency tone is the seventh. But this chord is way more dissonant than the major seventh. That probably has to do with the minor chord base. So, just as CM7 wants to resolve to C major, CmM7 wants to resolve to C minor.
Half diminished seventh:
Now, this chord has 2 tendency tones just like the dominant seventh. The root is a tendency tone and wants to resolve to the new root. The third isn't a tendency tone, but the fifth is a tendency tone with the fifth wanting to resolve to the new third.
Diminished seventh:
This chord takes seventh chord dissonance and tendency tones to the max. Because of the 2 overlapping tritones, a single diminished seventh chord is very dissonant, even more so when it moves to another diminished seventh. And, every single note in the diminished seventh is a tendency tone, because every note wants to move by half step.
So, what do you think of my tendency tone theory on the consonance and dissonance of seventh chords? Do you agree with my seventh chord ordering from most consonant to most dissonant?