In blues ‘dominant’ 7 chords (A7 or D7 for example) are more common than basic major, minor and sus chords. The A7, D7 and E9 ...

Let's go. The first 7th chord most of us learn is called just that: C7, G7, A7, etc. It seems reasonable to assume these consist of the root, 3rd, 5th and 7th of the scale, right? Wrong!

The concluding two examples shift to an A7 chord and introduce more melodic tension with the A Half/Whole Diminished scale (A Bb C C# Eb E F# G). This is a symmetrical scale based on a repeating ...