If you are fairly new to the guitar, you may very well look at a chord chart and see a chord with a “7” next to it. That indicates a very specific type of chord that has a wide...
If you are fairly new to the guitar, you may very well look at a chord chart and see a chord with a “7” next to it. That indicates a very specific type of chord that has a wide array of functions. Today, we will talk about its theoretical construction, some of its many uses and different ways you can play it all over the neck in different inversions.
This mysterious “7” next to the chord makes it a dominant 7 chord. To understand what that means, let us first go over some basic chord construction. Since we have an A7 chord, we'll explain this with its corresponding key signature, D major.
The Theory
In D Major, we have 7 notes with two of them raised. D E F# G A B C#
Typically, the dominant 7 chord is built off of the 5th scale degree, so we are thinking of this from the 5th mode of D Major, A Mixolydian. A B C# D E F# G
Keep that in mind, as we will come back to it. Now, let’s discuss some basic chord construction. Chords are typically built using a root, 3rd, and 5th.
In the key of D Major, that makes the following chords:
D = D F# A
Em = E G B
F#m = F# A C#
G = G B D
A = A C# E
Bm = B D F#
C#dim = C# E G
To create chords, you are basically taking notes in the key and skipping every other note until you get root, 3rd, and 5th.
The same principle applies with a 7th chord.
For D Major, here are the 7th chords:
Dmaj7 = D F# A C#
Em7 = E G B D
F#m7 =