What Are Dominant 7th Chords And 11 Ways Of Using Them In Progressions
- Yash
- Nov 11, 2022
- 8 min read
Music is all about conveying emotions and stories through sounds. Every good story needs a conflict to make the resolution stronger. It's very hard to keep the audience interested in a song that has static emotion throughout.
That is what "Dominant" means in music. The quality of a sound to have tension that has a strong pull towards another sound, i.e. the "tonic", to resolve the tension.
This is the broadest understanding of the concept, but it can have several specific meanings, which often causes a lot of confusion for beginners.
In this article, my focus is on explaining the construction and practical usage of Dominant 7th chords, but if you are interested in learning more about the concept of "dominant", I recommend that after you are done reading this article, you go through this discussion about different meanings of the word.
What Is A Dominant 7th Chord?
It is a 4-note chord made up of the following intervals:
1 3 5 ♭7
The notation that we use to denote them is simply a "7", or "Dom7"
For example C7, F7, B♭7, E7, etc.
In other words, it is a Major triad, with a ♭7 above it.
An E7 chord would have the following notes:
1 | E |
3 | G♯ |
5 | B |
♭7 | D |
Here are a few more:
C7: C E G B♭
F7: F A C E♭
G7: G B D F
A♭7: A♭ C E♭ G♭
What does a Dominant 7th chord sound like
Let's use G7 to understand what's happening inside this chord.
The notes in it are: G B D F
Here, G is the root, and there are 6 semitones between B and F. That means that in this chord, we have a Tritone.
This tritone gives it an unstable sound that just demands resolution. Let's hear it:
There are multiple ways of resolving a dom7 chord, but before we get to the fancier ways, let's take a look at where you encounter it.
Dominant 7th in the major scale
In the major scale, we have diatonic chords, i.e. chords that are made up of the notes that belong to the scale. If you are not familiar with the concept, you can read all about diatonic chords here.
Here is a quick explanation to find out the diatonic chords in a scale
In the C Major scale, we have the following notes: C D E F G A B C To make a chord on the 1st degree, we start with that degree itself, which is C. Then we stack a 3rd interval above that (the note has to belong to the scale), so we get E. Then another 3rd above that gives us G. This is the C-Major Triad.
Similarly for the chord starting on 2nd degree, we would get D-F-A, which is D minor triad.
Now, if we do the same thing (stacking 3rd) once more after making the triad, we would get a tetra-chord. So the 1st chord would become C-E-G-B, which is the C Major7 chord. It has the intervals 1-3-5-7.
Similarly on the second degree we get, D-F-A-C. Using intervals, this chord is 1-♭3-5-♭7, which is a minor 7 chord.
You can do the same thing for all degrees.
When we construct the diatonic tetra-chords (4-note chords) in a major scale, the chord built on the 5th degree has the following intervals: 1-3-5-♭7.
You can verify this with the C major scale.
C D E F G A B
The 5th scale degree is G. The chord built on it would have the notes G-B-D-F.
This is a dominant 7th chord, which is naturally found on the 5th degree of the major scale.
This chord has a very tense sound, because of the tritone. Not only that, one of its chord tones is B. That is just 1 semitone away from the tonic of the scale, so when we go from G7 to C, the movement feels incredibly satisfying since we have a leading tone movement as well as the resolution of the tritone happening at the same time.
It is exactly for this reason that a V7-I progression is often used to end phrases and songs.
Here is a I - vi - V7 - I progression, with a satisfying resolution at the end.
Using Dominant 7th chords in progressions
This is a rather versatile chord with a wide range of applications. Here are a few common methods:
1. Perfect Cadence in the major scale
As we just saw in the previous example, the dom7 chord is most often used in a major scale diatonically in a V7-I progression to end a phrase.
This is called the Perfect Cadence, where the phrase neatly ends with a classic resolution. It is probably the most common way of ending songs.
2. Ending on the tension: Imperfect Cadence
Just because the V7 chord creates tension, you are under no obligation to resolve it. You can just end the progression right there.
This is called the Imperfect Cadence, where you end a phrase on an unresolved chord, leaving the listeners wanting more. This is often done at the end of verses to create anticipation for the chorus. Here I have the following progression:
(ii - IV - V7 - V7) -- (ii - V7 - I - I)
The melody is made up of 2 phrases. The first one is a question phrase, which is ending on the V7 chord, making it an imperfect cadence. Then the 2nd phrase resolves the tension by ending on the I chord and using the perfect cadence.
When you use it in this way before a chorus, it is still getting resolved in the next phrase. However, you can just not have a resolution at all. End the song on a V7 chord, and leave the listeners hanging. Make sure your song demands such an ending, otherwise it would just annoy your audience.
3. Deceptive Cadence
After playing the V7 chord, the I chord is expected. But if you end the progression with some other diatonic chord instead, it is a pleasant surprise (generally speaking).
This is called the Deceptive Cadence, as it sets up expectations for the I chord, but throws them away immediately after. Usually, this is done with the vi chord.
Here's an example: I - iii - ii - V7 - vi.
4. Dom7 in the minor scale
Diatonically the 5th chord we get in a minor scale is minor 7. But to get a more satisfying resolution, we change it to the Dom7 chord, giving us a V7-i cadence in minor scales.
Check out the difference that it makes in this example. The original progression is
i - ♭VI - iv - v min7 - i.
Now I have changed the v min7 into a V7 chord.
i - ♭VI - iv - V7 - i.
To know more about this topic, read my post on Harmonic Minor. It gives a brief explanation of how this practice developed and more ways you can use the scale.
Apart from this, the dom7 chord also occurs naturally in the minor scale on the ♭7th degree, giving us the ♭VII7 chord.
5. Secondary Dominants
So far we have seen that there is only one naturally occurring dom7 chord in the major scale. However, you can use it as a non-diatonic chord too.
The function of a dominant chord is to create a pull toward the tonic chord. But that doesn't mean you have to be limited to the V-I relationship in a scale. You can treat any chord in your diatonic progression as a temporary tonic and play its relative 5th (V7) chord before it, creating a moment of tension and release within the progression.
This is called a "secondary dominant".
Here's an example of a chord progression involving a secondary dominant in the scale of C Major:
Em - G - A7 - Dm - G7 - C
I targeted Dm as a temporary tonic. Then I went to the P5th interval from D, which is A, and made a dom7 chord on it. This is notated as V7/ii (read V7 of 2) since Dm is the ii chord in the scale. Here, A7 is the secondary dominant of Dm.
If you liked that non-diatonic sound, check out my post on other ways of using non-diatonic chords.
6. Tritone Substitution
A tritone substitution is when we substitute one dom7 chord with another dom7 chord that shares the same tritone.
This is possible because the tritone gives the dom7 chord its characteristic sound, and if that tritone is common between two dominant chords, they can serve a similar function in the progression.
Take G7 for example. It is made up of G B D F. The notes that form the tritone in this chord are B and F.
Now consider D♭7. It comprises of D♭ F A♭ C♭. Here, the tritone is between F and C♭. However, C♭ is actually just another name for B. So it turns out that both of these Dom7 chords share the same tritone (This is not a surprise since the tritone is a symmetric interval. It is 6 semitones, no matter which one of the two notes is lower).
Therefore, D♭7 is the tritone substitute for G7. We know that D♭7 resolves to G♭ Major and G7 resolves to C Major. But since they are substitutes for each other, they can be used for each other's resolutions.
Notice that their roots (G and D♭) also form a tritone with each other.
We can use this observation to easily find the tritone substitute of any dom7 chord. Just play the dom7 chord whose root is a tritone away from the chord that you want to replace.
Like C7 and G♭7, F7 and B7, etc.
This can be done for the V7 chord in the scale, or for a secondary dominant. The method remains the same.
I've used D♭7 to replace G7 in the following progression to target C:
Em - Dm - D♭7 - C
This leads to the last three chord roots going down in a chromatic motion (D, D♭, C).
7. Dom7 in blues music
In blues music, dominant chords became the staple of the genre. Pretty much every chord in a blues progression is dom7.
In minor twelve-bar blues, this is the progression:
Composers often use the relevant blues scale to improvise/compose melodies over this progression.
If you enjoy blues music, you can learn about its theory here.
8. Secondary 2-5 progression
You might have heard about the famous 2-5-1 progression in jazz. In a major scale, it is
ii min7 - V7 - I Maj7
This progression can be used as an extension of the secondary dominant concept.
When you want to target a chord, you treat it as a temporary tonic. Then before you play that chord, you play the ii-7 relative to it, and then the V7 chord relative to it.
For example, if you want to target F Major in any progression, you can precede it with Gm7 and C7.
Here's one such progression:
C - Dm - G - F - C
And it gets transformed into:
C - Dm - G - (Gm - C7 - F) - C
You can even combine this method with the tritone substitution method, and substitute the C7 chord with F♯7 in the previous example.
C - Dm - G - (Gm - F♯7 - F) - C
9. Backdoor 2-5
In a major scale, instead of using ii - V7 - I, you can use IV - ♭VII7 - I. This is called the backdoor ii-V progression, and if you are interested in learning more about it, check this out.
10. Aug7 chord
Wherever you have a dom7 chord, you can replace it with an augmented 7th chord by simply raising the 5 to a ♯5. This makes the chord even more dissonant and mysterious.
The intervals that make up the Aug7 chord are: R 3 ♯5 ♭7
Example: A Aug7 chord is A C♯ E♯ G, and you can use it in place of A7 in the following progression:
Em - G - A7 - Dm - G7 - C
Now, Changing A7 to A+7
Em - G - A+7 - Dm - G7 - C
11. Chaining 2-5's
What is better than one dom7 chord? You are right, it's several dom7 chords.
We can chain together multiple 2-5 progressions to create a turnaround. This is a fairly common technique in jazz music, but outside of the genre, it might not work so well.
This is a more complicated topic that is outside the scope of this article, but Rick Beato does an amazing job of explaining it in his video Elements Of Jazz.
Those are some common ways of using the Dom7 chord, but feel free to experiment and find more of them.
Conclusion
The dominant 7th chord is made by stacking a ♭7 over a major triad. In other words, the intervals in it are 1 3 5 ♭7.
It has a dissonant sound that just demands resolution, and we learned several ways of finding that resolution.
It is found naturally on the 5th degree of a major scale and resolves to the 1st chord.
You can also make it on the 5th degree of a minor scale to get a stronger V-i resolution.
There are other applications like secondary dominants, tritone substitutions, etc. that allow us to use this chord non-diatonically.
If you found this article useful, please subscribe to my blog for more content like this. In another article, I would be looking at the ways you can compose melodies over dominant chords, so be on the lookout for that. Thank you for reading.
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