The last two bars of a blues have a job: send the listener round again. What goes there is almost always the same idea — one voice walking down a semitone at a time while the root stays put above or below it — and once you can play one, you can play the ending and the intro too, because they are the same two bars used differently.
Where it goes
With a turnaround in A: A7, A7, A7, A7, D7, D7, A7, A7, E7, D7, A7 then D7, A7 then E7.
The last two bars split in two, so the form turns back toward the top. The heavier outlines are the two bars that differ from the twelve-bar blues. Two of its bars hold two chords.
The chord changes in the last bars are small. What makes a turnaround sound like a turnaround is the line moving through them, not the chords themselves.
The line
One voice down, one voice still
A turnaround, over A7: ♭7 G, 1 A, 6 F♯, 1 A, ♭6 F, 1 A, 5 E.
Seven notes over four beats. It starts on the ♭7, and comes to rest on the 5, with vibrato. The dashed lines are the notes of A7, and that last note is one of them.
Read it as two parts played by one hand. The voice on the second string falls ♭7, 6, ♭6, 5 — four notes a semitone apart — and between each of them the root answers on the string above. Two of those four are outside your scale. They are passing notes, which is what a line moving by semitones is made of, and they sound wrong only if you stop on one.
It lands on the fifth, which is the chord that hands the form back to bar one. That is the whole mechanism: a line that has to keep falling, arriving on the one chord that cannot be home.
The same two bars, three ways
Play it at the end of a chorus and it is a turnaround. Play it once before you start and it is an intro — the band comes in on bar one as if the form had already been going. Play it at the end and stop on the root instead of the fifth, and it is an ending. Nothing about the line changes but its last note.
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