Blues Chords In G

In this lesson, let's learn the chords for Blues in G - G7, C7 and D7.
G is the Blues key when playing a C harmonica in second position.

These Blues chords take the form of dominant seventh chords which is accomplished by taking a major triad and adding a flatted seventh to the chord.

Starting with G7, the notes of the chord are G, B, D, and F.
In the key of G, the seventh note is F#. To make the dominant 7th chord, we flat the 7th to F.

C7 is made up of the notes C, E, G, and Bb.
B is the 7th note in the key of C. We flat it to Bb to form C7.

D7 is made up of the notes D, F#, A, and C.
C# is the 7th note in the key of D. Flat it to C to form D7.

Learn each of these chords and practice switching between them. Play the notes of each chord individually so that they're clean.

12 Bar Blues In G

Here is a basic 12 Bar Blues progression in the key of G.
First 4 bars: All G7
Next 4 bars: C7 for 2 bars, G7 for 2 bars
Last 4 bars: 1 bar each of D7, C7, G7, D7
Then repeat

G7 | G7 | G7 | G7 |
C7 | C7 | G7 | G7 |
D7 | C7 | G7 | D7 |

Now let's play these chords to a 12 Bar Blues progression. Sing the roots of the chords as you go.
Listen to the new quality of the dominant 7th chord