YOU KNOW IT ALL—YOU JUST DON’T KNOW WHAT TO DO WITH THE information. If you read my last two Woodshed columns, you’re familiar with immutable truths about diminished scales: They come in two varieties, whole–half and half–whole; they repeat themselves every minor-3rd interval; and they can sound predictable and mechanical when overused.
Why bother with diminished scales? Because they’re so functional–like a secret ingredient that binds the gumbo of harmony. The étude this month, “Diminished Gumbo,” uses three different diminished scales: F whole–half, Bb whole–half, and C whole–half. Each chord of the 12-bar blues form is embellished with the b9 sound. As you recall from my two previous columns, a chord symbol with 7b9 or 13b9 suggests the use of the half–whole diminished scale (think of the scale from the root of the chord). There are other scales that could work, but the diminished scale starting with a half-step interval is the best fit for a dominant-7 chord with the b9 and n13.
Work slowly through the solo étude “Diminished Gumbo,” taking time first to understand the theory behind the notes, and then to learn the sound of the three diminished scales. Your mastery of the diminished scale will provide countless hip options for your bass lines, fills, and solos.
Note the following:
Bars 1–2 The first chorus of “Diminished Gumbo” is a soloistic, beboppish eighth-note line. The étude begins with an arpeggio up the F7 chord, landing on the b9 (the note Gb) in bar 2.
Bars 3–4 The line starts on the note Eb (the b7 of the F7b9 chord) and snakes down the F half–whole diminished scale.
Bar 5 This melody mirrors the diminished lick in bar 1, transposed up an interval of a 4th here to fit the Bb13b9 chord.
Bar 6 The #11 (the note En) and the 13 (the note G) characterize the Bb13b9 sound.
Bars 7–8 This is a classic bebop lick using the diminished scale.
Bar 9 The inversion of the C triad (the notes G, E, C) is followed by an inversion of the Gb triad (the notes Bb, Gb, Db). This is an example of using a triad pair to outline the sound of a complicated chord structure. The notes of the Gb triad provide the b7 (Bb), #11 (F# or Gb), and b9 (Db) of the C13b9 chord.
Bar 10 Here the Bb13b9 is outlined using a triad pair: the root-position Bb triad and the root-position E triad. The notes of the E triad provide the #11 (E), b7 (Ab or G#), and b9 (B or Cb) of the B13b9 chord.
Bar 12 Diminished licks can also sound melodic, as heard here. Db is the b9 and Bb is the b7 of the C13b9 chord. On beat four the chord resolves to the notes A and F, which belong to the F13b9 chord. This final lick sets up the walking line that begins in bar 13.
Bars 13–14 The second chorus of “Diminished Gumbo” starts with a descending walking line using the F half–whole diminished scale. The note B in bar 14 stands out because this is the spot in a blues where the harmony will often move to a IV chord (Bb7). By landing on the note B, the line emphasizes the #11 found in the diminished scale, and broadcasts the diminished sound.
Bar 15 The notes Ab and A play with the ear, suggesting both a major and minor sound on the F chord. The F half–whole diminished scale does indeed contain F minor (F, Ab, C) and F major (F, A, C) triads. This major–minor duality gives the diminished scale its urbane, complex-yet-bluesy sound.
Bars 17–18 This is a three-note sequence, repeated and transposed up in minor-3rd intervals through the Bb half–whole diminished scale. Since the walking line is in 4/4, the repeated three-note patterns create an across-the-bar-line rhythmic feeling.
Bar 19 The notes Ab and Gb outline the #9 and b9, which characterize the diminished scale.
Bars 21–22 As in bar 15, the notes here play on the duality of the major-and minor-3rd intervals.
Bars 23–24 The line moves up an F triad arpeggio, but finds the b9 (Gb) on beat four. In bar 24, the line juxtaposes the Gb triad over the sound of the C13b9 chord. The notes of the Gb triad provide the altered notes of the C13b9: Db (b9), Bb (b7), Gb (#11 or b5), and E (3rd).
John Goldsby is teaching in July at the Aebersold Summer Jazz Workshops in Louisville, Kentucky, and the Sligo Jazz Workshop in Ireland. Introduce yourself in person, or online at