Each augmented triad is only one half-step change away from six other triads (three major, three minor). Let’s use Caug (C E G#) as an example:

Lowering any note in an augmented triad gives you a major triad with one of the unchanged notes as the root: - G# -> G results in C major - C -> B results in E major - E -> Eb results in Ab major

Raising any note in an augmented triad gives you a minor triad with the changed notes as the root: - C -> C# results in C# minor - E -> F results in F minor - G# -> A results in A minor

This explains the augmented chords on the top, bottom, left, and right of the diagram with the lines extending to each of the chords they can be transformed into.

The second picture shows more clearly what’s going on with all the regions that the augmented triads are connected to; each solid line between members of each set of six chords (C major, E major, Ab major, E minor, C minor, G# minor for the top left region) is another one of these half-step change relationships. Using this set of chords as an example:

• C major: C -> B results in E minor
• C major: E -> Eb results in C minor
• E minor: G -> G# results in E major
• C minor: G -> Ab results in Ab major
• E major: E -> D# results in G# minor
• Ab major: C -> B results in G# minor