12 bar blues progression

The 12 bar blues progression consist of 12 repeated bars. Musicians use this progressions as a common standard reference frame. A 12 bar blues form is most often in 44. This means that there is 4 counts in each bar. The 12 bar blues progression use step 1, 4 and 5 in the key in which you play. If you play in the key of E, the chords are E, A and B, as this is step 1, 4 and 5 in the E-major scale. We use roman numbers (I, IV, V) to identify the chords in a chord progression. Basically, we can play a minor seventh on all the chords in the blues form. The form: A 12 bar blues progression in it's simplest form looks like this
I7I7I7I7IV7IV7I7I7V7V7I7I7
This form is eg. used in the song Johnny B. Goode af Chuck Berry. In the form below V7 in bar 10 is changed to a IV7 which is often used.
I7I7I7I7IV7IV7I7I7V7IV7I7I7
This form is eg. used in the songs Blue suede shoes, og Hound dog by Elvis. Let's now change the last chord to a V7 chord, to head back to the beginning. This is called a turn-around chord, because it makes the song start over again. You can not end the song on this chord, so you will now play the song again or end the song in bar 1. Try to play the progression in the key of E and A, by changing the roman numerals with the correct chord names based on the root.
I7I7I7I7IV7IV7I7I7V7IV7I7V7
Below we play a IV7 chord in bar 2, which also is very commonly used. Try to play the progression in the key of E, A and D.
I7IV7I7I7IV7IV7I7I7V7IV7I7V7
Lysten to others playing the blues and try to identify wether they use I7 or IV7 in bar 2 and 10, and wether they play V7 in bar 12 to head back to the beginning. You will soon discover that not all blues songs fit into the forms that we have gone through. You should remember that this 12 bar blues form is a template, which is often used as a starting point in the blues genre. Practice tips: 1. Practice each hand separately 2. Practice each bar separately. Repeat until it feels natural. 3. Start slowly, and increase the pace gradually. 4. Play the progressions with straight eights and in shuffle.

The blues progression

Progression variation 1

Progression variation 2