7th chords are a great addition to your chordal arsenal and by now, you should know how to play the basic CAGED chord shapes. The theory behind these is that they are built up of the 1st, 3rd and 5th degrees of the scale. Well, if we then add the 7th degree in, we get 7th chords. And who doesn’t want to learn new guitar chords?
Learning the chord shapes is all well and good, of course. But it’s important to know how they are built up so that you can learn where to place them in your playing and composition as a guitarist.
Music theory isn’t easy though. There’s no way I’ll tell you otherwise. But just like that tricky phrase on guitar, it’s important to take it one step at a time. Learning theory in tiny pieces helps to build on those “eureka!” moments as you begin to understand how guitar chords and scales work together.
A Quick Recap
A chord is essentially 2 or more notes played at the same time. Triad are made of three individual notes and, as previously mentioned, are built up of the 1st, 3rd, and 5th degrees of the scale. So the chord is built up in intervals of 3rds.
In this C Major, you can see the individual degrees of the scale that build up the triad. In many instances, you’ll play more than one of each degree. C plays the 3rd and 1st degrees twice. To turn this into a minor chord, you flatten the 3rd.
To learn a little more about intervals, how they relate to each other and how they build chords, check out a recent blog post here.
Let’s talk 7th chords…
7th chords typically convey a bluesy or jazzy quality. This is due to the 7th degree of the scale. Additionally, the 5th diatonic chord available in a key, is known as the dominant chord. So say in the key of C, you’ll find the following chords;
| Chord Degree | Tonality | Name | Shorthand |
| 1st | Major | C Major 7 | CM7 |
| 2nd | Minor | D Minor 7 | Dm7 |
| 3rd | Minor | E Minor 7 | Em7 |
| 4th | Major | F Major 7 | FM7 |
| 5th | Major | G Dominant 7 | G7 |
| 6th | Minor | A Minor 7 | Am7 |
| 7th | Diminished | B Diminished 7 | Bdim7 |
Aside from your dominant chord, which has a major tonality, your 7th chords typically read out the same as their triad counterparts when looked at diatonically.
When building your 7th chords, your intervals will be as follows;
- Root
- Third (major or minor third from the root)
- Fifth (diminished, perfect or augmented fifth from the root)
- Seventh (major, minor or diminished from the root)
If we stick with our trusty C Major chord, the notes we have are;
C – E – G
Each note has an interval of a 3rd between each, with the interval from C to G being a perfect 5th. This is a lovely 7 semitones away from the root note. Continuing on from there, we need to head all the way up to 11 semitones to find out 7th. So with a C Major…
C – E – G – B
Let’s look at how that changes our C Major triad pictured earlier on:
By taking out the 1st degree of the chord found on the B string, we change the C to a B which gives us our 7th. Thereby, changing the C Major to a C Major 7
What about minor 7ths?
Well let’s think about how the minor triad is built;
1st – minor 3rd (or b3) – 5th
The minor 7th chord flattens the 7th degree of the scale as well. Let’s look at a minor triad and it’s minor 7th side by side for comparison.
On the left, you’ve got an E minor triad shape. You can clearly see the individual intervals from the 1st to the 5th with that b3 in between. On the right, we’ve added a b7 to give the 7th chord it’s minor tonality.
Dominant 7th chords
A dominant 7th chord is built up of the following intervals;
1st – 3rd – 5th – minor 7th (b7)
So it’s sort of a blend of a major 7th and a minor 7th. It’s arguably the most important of the 7th chords as in composition, it typically drives a song’s chord progression toward a sense of resolution. Let’s have a look at an example of a major triad and it’s dominant 7 counterpart.
As we’re sticking to the key of C Major, your 5th chord is a G7. On the left is your G major triad in the open position. By bringing the root played on the top e string down to the 1st fret, we find our b7 note, giving the dominant 7th tonality.
Diminished and half diminished
We’ve covered the 3 main types of chord you’ll use when learning 7th chords. The 7th diatonic chord available to you, much like when learning triads, is of course the diminished 7. In C major, this would be Bdim7. The intervals for diminished chords would be;
1st – b3 – b5 – dim7
Whereas a half diminished chord keeps the b7 from the minor 7th.
1s – b3 – b5 – b7
These are commonly referred to as m7b5 (minor 7 flat 5) chords. So the difference between these two chords, is that the 7th is flattened again from the minor and is more akin to a 6th.
As we’ve only looked at chords in the key of C, click here for an article that covers a few of the common 7th chord shapes.
Summary
7th chords are a great way to jazz up your chord progressions and expand upon your chord vocabulary. You’re also not limited to using either triads or 7th chords, so mix them up a little and see what you can come up with!
Good luck and happy playing.