A blues has three chords and two moments where one becomes another: bar five, where the second chord arrives, and bar nine, where the third does. Everything else is a return home. If you can hear those two coming, you can play them rather than notice them a beat late.
The twelve bars, with the two changes in them
The twelve-bar blues in A: A7, A7, A7, A7, D7, D7, A7, A7, E7, D7, A7, E7.
Four bars of I, two of IV, two of I, then V, IV, I and V to turn the form around.
The second chord is built on the fourth note of the key and the third chord on the fifth, which is where the numbers come from. In A that is D and E, and both of them are already in your box, along with A itself. The roots of all three chords are notes you have been playing since Part 2 without thinking of them that way.
The five notes, named
The keyboard shows the same five notes as a shape you can see. The colored keys are the A minor pentatonic scale, and the pale keys are the rest of A natural minor.
What the change sounds like
When the chord moves to D7 at bar five, the music lifts. Nothing gets louder — the bass has simply gone up a fourth, and the note that was the top of the chord is now the bottom of a new one. At bar nine it moves again, up another step to E7, and that one sounds like the end of something rather than the middle.
Your own notes tell you when it has happened, if you are holding the right one. The ♭7 rests over the first chord and leans over the second. The fourth leans over the first and is home over the second. Hold either one across bar four into bar five and the change plays itself.
Twelve bars to listen to
Band · twelve-bar blues in A · shuffle · 84 beats a minute
A band plays the twelve-bar blues in A, shuffled, at 84 beats a minute: A7, A7, A7, A7, D7, D7, A7, A7, E7, D7, A7, E7.
Drums, bass and the shuffle riff, round the twelve-bar blues in A. The bass walks each chord from its root: 1, 3, 5, 6, ♭7, and back down.
This lesson was drafted with the help of AI, so it may contain a mistake. Its diagrams are drawn by Everyfret’s own software. How Everyfret is made