Twelve bars are a lot to count in a row, and players rarely think of the form that way. They hear it as three lines of four bars, the way a verse of a song falls into lines. Once you can hear the lines you always know where you are, because each line begins on a different chord.
The twelve bars as three lines
The twelve-bar blues in A: A7, A7, A7, A7, D7, D7, A7, A7, E7, D7, A7, E7.
Each row is one line. The first stays on the I, the second begins on the IV and comes home, and the third begins on the V and turns the form back to the top. The letters at the left show which lines match.
A line, the same line again, and an answer
A blues verse is usually sung to these three lines. The singer sings a line over the first four bars and then sings the same words again over the next four. The third line is different. It answers the first two, often finishing the thought they started, and that is why it sounds like the end of the verse. The shape is called AAB, one letter for each line, with the repeated letter for the repeated words.
The repeat does not sound like a repeat, because the chord under it has moved. The second line begins over the IV, so the same words are heard against different notes in the band, and they take on a new color. Listen for this when you play the form: bar five is where the ground shifts under a line you have already heard.
Two bars to sing, two to answer
Each line has a smaller shape inside it. The singer usually fills the first two bars or a little more and leaves the rest of the line open, and the open bars are where the guitar answers. This is called call and response. The voice calls, the guitar replies, and then the guitar gets out of the way for the next line.
The notes you answer with
Box 1 covers frets 5–8 and holds twelve notes.
This position covers frets 5 to 8, and every note of A Minor Pentatonic lies under one hand there. Five positions like it cover the whole neck, and this is the first of them.
You can hear the same shape without a singer. Play a short phrase from the box for the first two bars of a line and then stop. The silence that follows sounds like a question waiting for its answer, and learning what to put there is what the second part of this course is about.
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