Using Dominant 7th Chords on Guitar


What is a Seventh Chord?

A dominant 7th chord is one type of 7th chord. So before you learn about the dominant 7th you must know what a 7th is.  If you take any type of triad (major, minor, dim, aug, whatever you want) you have three notes.  The root, the 3rd, and the 5th.  If we go one step further and add an interval of a 7th from the root, we will have a 7th chord. NOTE: do not confuse a 7th chord with the seven chord, which is the chord formed on the 7th note of a scale.

What is a Dominant 7th Chord?

The dominant 7th is a unique type of 7th chord.  The easiest way to see what it is is to look at all of the diatonic 7th is a key.  We’ll do C major to keep it simple.

 

7th B C D E F G A
5th G A B C D E F
3rd E F G A B C D
root C D E F G A B
  I ii iii IV V vi vii
type of 7th Maj7 min7 min7 Maj7 dom7 min7 half-dim7

As the chart says, there are 4 types of seventh chords that naturally appear within a major scale: Major, minor, dominant,  and half-diminished.  Major 7ths occur on the I and IV of the scale. The minor on the ii, iii, and vi. The dominant on the V. And the half-diminished on the vii.  Here’s another chart to explain the differences between the types of 7th chords.

 

Added 7th Major 7 Minor 7 Minor 7 Minor 7
Triad Type Major Minor Major Diminished
M7 m7 dom7 half-dim7

This chart is pretty simple to read.  If you want to form a Maj7 chord, take a major triad [ C E G ] and add a  major 7th [ B ]. If you want to form a min7, take a minor triad [ D F A ] and add a minor 7th [ C ]. If you want to form a dominant 7th, take a major triad [ G B D ] and add a minor 7th [ F ].  If you want to form a half- diminished 7th, take a diminished triad [ B D F ] and add a minor 7th [ A ].  In conclusion, a dominant 7th is the 7th chord that occurs naturally at the V of the major scale. There is only one diatonic dominant 7th chord per major key (although you can use others).  A dominant 7th chord is made up of a major triad with an added interval of a minor 7th.

Why is it called the Dominant 7th?

The fifth tone of a major or minor scale is called the dominant.  Since the dominant 7th can be build from the V of a major scale, it is known as the dominant 7th.

What is the notation for the Dominant 7th?

The dominant 7th is notated as just a 7. Therefore a G dominant 7th would be notated as G7, as opposed to GMaj7 (major 7) and Gmin7 (minor 7).

What’s the difference between a Major 7th and a Dominant 7th?

The differences can be a little hard to understand, especially if your not good at building the chords with intervals as I described above.  So to make to difference clear I’ll do a straight-up comparision between the 2. We already know for the chart above that both kinds of 7ths are build from a major triad. One has a major 7th added, one has a minor 7th added.  But what exactly does that look like.  We are going to use GMaj7 and G7. As we already said G7 is formed from the C Maj scale [ C D E F G A B ].  We have also said that G7 is as follows: G B D F.  G Maj7 however is formed from G Maj [ G A B C D E F# ].  Therefore we get G B D F#.  As you can see,  in G7 we use the minor 7th [ F ], and in GMaj7 we use the Major 7th [ F# ].

Why is the Dominant 7th chord important?

The dominant 7th chord is important because it contains the “key-defining tritone.”  A tritone is an interval of a diminished 5th ( or augmented 4th ). A tritone exists in every dominant 7th chord between the 3rd and the 7th of the chord.  These notes are important for two reasons: 1) in traditional voice-leading they would resolve to the root and 3rd of the I chord. We won’t be concerned with this since its very hard to use voice leading techniques on the guitar. 2) The notes of the tritone are key defining and clearly state what key you are in.  For example in C maj the dominant is G7 [ G B D F ].  If we look at the 3rd and 7th of this chord [ B, F ] we will find that between these two notes there is an interval of a diminished 5th, or a tritone. Not only that but these two notes define the key of C Maj. Why is that you ask? Well, in no other major scale will you find both a B and an F.  To prove this lets take the two closest related major scales to C: G and F major.  In G maj there is B but alsoan F#, in F Maj there is an F but also a Bb.  Therefore the notes of F and B, which are contained in the diatonic dominant 7th chord of C Maj, are only found in C Maj, and therefore define the key.

How can I use the Dominant 7th Chord?

The Dominant 7th chord always leads to I.  Therefore if you have a V- I or V-i progression, you can substitute V7s for the Vs. This would give you V7- I or V7- i.  This is the best way to use the V7 of the scale you are playing with.

What does a Dominant 7th Chord look like on Guitar?

I’ve given aa couple of basic forms of dominant 7th chords below. Keep in mind that these are definately not the only ways to play dominant 7th chords on the guitar.  There are many open dominant 7th chords that will probably sound fuller than these but I just wanted you to have some basic ones.  Just move the root (blue dot) to the note you want to be the root of the chord a la a barre chord.

Bonus: How to use Dominant 7th Chords to make Dorian Mode Progressions

Obviously there are a lot of interesting ways to use dominant 7th chords.  One of my favorites is to use them to create a dorian mode progression.  If you haven’t read my lesson on Dorian Mode do so here.  One of the main differences between the natural minor mode and the dorian mode is the iv chord.  Let’s take A minor [ A B C D E F G ]. The 7th chord build on the iv of this scale is Dmin7 [ D F A C ].  Now lets look at A Dorian mode [ A B C D E F# G ].  The 7th chord build on the IV of this scale is D7 [ D F# A C ].  Therefore using a dominant 7th chord on the 4th scale degree will result in a dorian sound.  A sample progression is shown below in A Dorian.

e||--5--|--3--|--5--|--5--||
B||--5--|--3--|-----|-----||
G||--5--|--4--|--5--|--5--||
D||--7--|--5--|--4--|--4--||
A||--7--|--5--|--5--|--5--||
E||--5--|--3--|-----|-----||
    Am    GM    D7    D7

There you go. Have fun with the dominant 7th chord.  NOTE: I like doing these music theory lessons because I find that a lot of people want to learn some theory and it can be tough to get reliable info from people who actually know their stuff. I may not know all the theory there is to know, but I know quite a bit. If there’s anything theory-wise that you don’t understand, feel free to comment on it and I’ll get a lesson up on the topic.

If you have any questions please email me at mdguitarteacher@gmail.com.

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7 Responses

  1. THANK YOU :)

  2. Hi..You have given a great information on dominant 7th chord guitar, its nice to come across your site. You have given beautiful information in the form of chart which is easy and quite simple.

  3. Thank you for the clarity of your site. I had a small jam session with a beginner guitarist and he argued me down on the facts that your site clarified and confirmed for me!! Thank you very much!!

  4. […] We’ve already been over dominant chords.  If you missed that make sure you get up to speed here. Today we will be taking the next step and look at some secondary […]

  5. Very clear and I am saving this as a reference. The C Diatonic Scale is easy because it has no sharps or flats. Charts are excellent Graphic Organizers like the one you have used. I need a way/method to find the other keys; The key of G has F# and we see this is critical to form these 7th cords. Thank you very much.

  6. hi thanks a lot for sharing your wisdom. This would be of great help to bring my interest in guitar 10 steps further

  7. I wanted to know the difference in terms of how they sound so this wasn’t really helpful @ all

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