Diminishing Returns

Or, worse yet, an F#b9/13 or—Jaco help you—an Eb7#9/b9? All of these chords are derived from the same scale—and it’s why, my friend, you really need to know your way around the diminished scale.

As you might recall from Victor Bailey’s Lesson in September ’05, the diminished scale is an eight-note scale built symmetrically in a half-step, whole-step pattern. While Victor’s lesson focused on one variant of the scale, the “whole-half,” this time let’s look at its counterpart, the “half-whole.” Look at Ex. 1 and check out how it is constructed.

There are several “hidden” chords lurking inside the diminished scale. In addition to the C7 chord, you can also find the notes of the E7, G7, and A7 chords. There is a Cdim7 chord (C, E, G, A) contained in the scale as well as a Ddim7 chord (D, E, G, B). These two diminished chords on top of each other give this scale one of its names from the bebop era: the double-diminished scale. Most players today refer to this scale as the half-step/whole-step diminished scale.

Ex. 2 is based on the first section of the Duke Ellington standard “Caravan.” In this progression, the C79 is acting as the V chord, or the dominant sound that will eventually resolve to Fm7, the I chord, in bar 13. To get this progression in your ear, check out Oscar Pettiford with Thelonious Monk (Thelonious Monk Plays Duke Ellington, Riverside), Art Blakey & the Jazz Messengers (Caravan, Riverside), or any of the original Ellington versions of the tune.

The example starts on the root, C, and moves up the diminished scale to D (the 9) on beat three in bar 2. Bar 5 moves down the scale, emphasizing the F# (the #4), E (the 3rd), and D (the 9). In bar 8, the line begins on C but moves to a descending G triad arpeggio. Beat three lands on G, and then outlines the descending G triad arpeggio again. This is a common technique: By superimposing other chords contained in the scale, like the G triad on top of the C7, you can emphasize the complex color of the diminished sound.

Bar 11 begins on the 9 and #9 (D and E) and then moves downward in a typical scale pattern in 3rds. In bar 13, the progression finally resolves to Fm7, the I chord—ah, home base. Recognize the scale on the Fm7 chord? Right—it’s the plain ol’ funky F minor blues scale.

Start slowly and learn the theory and sound of the diminished scale. Once you master this scale, you’ll have a new vocabulary at your disposal. Next time we’ll take another look at the extremely useful—but hard to deal with—minor 7 5 chord. Until next time, keep swingin’!