Cycle of 4ths

So far, we’ve looked at a selection of chord progressions that form the basis for hundreds of jazz compositions. We’ve examined the power of V7-I motion for intros or outros; Major and Minor blues sequences, with their I to IV and V-I resolutions; the II-V-I in both Major and Minor forms; and, just last month,‘Rhythm’ changes, with its III7-VI7-II7-V7 I bridge. All these sequences resolve on a perfect 4th.

The 4th interval is particularly powerful. Not only is it the basis for the majority of functional harmony, but if you go around this pattern in an unbroken cycle of 12, you’ll return to exactly where you started, having visited every key in the process. This sequence has huge transpositional logic and value. And the guitar is well suited to this task, given that all the strings are a 4th apart (E-A, A-D etc) with one exception between the third and second strings (G-B = maj 3rd). If you quickly glance at Example 2) you’ll see clearly