The Blues Form
Harmonically the blues is very simple, with only 3 different chords that is divided over a form of 12 bars. There is different types of Blues, 32 bar blues, 16 bar blues, but in this lesson we will focus on the most common 12-bar blues.
Let’s take a look at this 12-bar blues in E major.
The blues is played in the time signature 4/4, which means that you count “1 2 3 4” in each bar.
12-bar blues in E.

Chords
Here is the following chord diagrams:
7-chord



You can also play all these chords as 7-chords. Which means that you add an extra note to the chords, to give them a different sound. Then the 12-bar blues will look like this:

Here is the chord charts for the 7-chords:


