Module 9: Scales and modesLesson 5advanced⏱ 90 min + two weeks of drills

Symmetric scales: diminished and whole tone

The whole-half diminished scale for dim7, the half-whole for 7b9 and 13b9, the whole-tone scale for 7#5, why their shapes repeat every three or two frets, and the patterns that make them sound like jazz rather than exercises.

Why symmetry is a gift to guitarists

Every scale so far has been built from a key: seven notes, a tonic, a hierarchy. The two scales in this lesson are built from a pattern instead. The diminished scale alternates whole and half steps; the whole-tone scale is nothing but whole steps. Because the pattern repeats inside the octave, the scale has no single tonic, the same scale serves several chords at once, and, most usefully for you, the fingering repeats up the neck: every three frets for the diminished scale, every two for whole tone. Learn one shape and you have the whole fretboard. That symmetry is also what these scales sound like: rootless, floating, tense. They are the classic sounds over dim7, over dominant chords with a b9, and over dominant chords with a #5, and they are the dominant-chord vocabulary that bebop and everything after it used most, more than harmonic minor and alongside the altered scale.

Three scales, two patterns

Whole-half diminished (W H W H W H W H) is the scale for a diminished seventh chord. It is eight notes: the four notes of the dim7 chord plus a note a whole step above each one. Every chord tone has an available tension a whole step above it, so it has no avoid note. The engine spells the 7th degree as a double flat (bb7, the diminished 7th) because a dim7 chord is built from stacked minor 3rds; on the fretboard it is simply the note a whole step below the major 7th.

Half-whole diminished (H W H W H W H W) is the same eight notes started one step later, and it is the scale for dominant chords with a b9: 7b9, 13b9, 7#9, 7b9#11. Spelled from the dominant root it gives R b9 #9 3 #11 5 13 b7, which is every altered 9th and 11th together with the natural 5 and 13. Compare it with the altered scale from the previous lesson: both have b9, #9 and #11, but the half-whole keeps the natural 5 and 13, where the altered scale has the b13 and no 5. The half-whole is the brighter, more "inside" of the two altered-dominant sounds, and the one that works over a blues.

Whole tone (W W W W W W) is six notes: R 2 3 #4 #5 b7. There is no perfect 5th and no perfect 4th; it is the scale for 7#5 and 7b5 chords, and for the augmented triad. Every note is a whole step from the next, which is why nothing in it sounds like a resolution.

The symmetry, and what it means on the fretboard

A diminished scale repeats itself every minor 3rd (three frets). Move any diminished-scale fingering up three frets and you are playing the same eight notes. A whole-tone scale repeats every major 2nd (two frets). Two consequences:

1. There are only three diminished scales and two whole-tone scales in all of music. C, Eb, F# and A whole-half diminished are the same scale; C and D whole tone are different, C and E whole tone are the same.
2. One diminished scale serves four dominant chords. G half-whole contains the chord tones of G7b9, Bb7b9, Db7b9 and E7b9, because those four roots are a minor 3rd apart. The same scale is also B, D, F and Ab whole-half, so it serves Bdim7 and its three inversions. When you play a line from this scale over G7b9, you are also playing the tritone substitute Db7b9, and the ear hears both.

Look at the whole neck. The half-whole pattern from G is shown with degree labels; find the same pattern of dots starting at fret 3, at fret 6, at fret 9 and at fret 12.

Half-whole diminished for 7b9 and 13b9

The chord-scale table shows the dominant chords that take the half-whole scale, together with dim7, which takes the whole-half from its own root (the same notes, a minor 3rd apart).

Here is the scale in position III, from G, two octaves and back.

\tempo 92
.
\ts 4 4
:8 3.6 4.6 6.6 2.5 4.5 5.5 2.4 3.4 | 5.4 6.4 3.3 4.3 6.3 3.2 5.2 6.2 | 3.1 4.1 6.1 4.1 3.1 6.2 5.2 3.2 | 6.3 4.3 3.3 6.4 5.4 3.4 2.4 5.5 | 4.5 2.5 6.6 4.6 :2 3.6 |

The characteristic patterns

Scales played straight through are exercises; diminished scales played straight through are exercises that sound like a film score. What makes them sound like jazz is the symmetric cell: a short figure played, then repeated a minor 3rd higher, as many times as you like, because the scale guarantees that the transposed cell is still in the scale. The classic cell is the first four notes, R b9 #9 3, which is "half step, whole step, half step" and sits on two strings.

\tempo 132
.
\ts 4 4
:8 5.4{ch "G13b9"} 6.4 3.3 4.3 3.3 4.3 6.3 3.2 | 2.2 3.2 5.2 6.2 5.2 6.2 3.1 4.1 | :2 3.1{ch "Cmaj7"} :4 5.2 r |

Now the same cell exploited for its fretboard symmetry: one fingering on the two lowest strings, moved up three frets each time. This is the drill that makes the scale physical; once you can do it with this cell, do it with every cell you invent.

\tempo 112
.
\ts 4 4
:8 3.6{ch "G7b9"} 4.6 6.6 2.5 6.6 7.6 9.6 5.5 | 9.6 10.6 12.6 8.5 12.6 13.6 15.6 11.5 | :2 15.6{ch "Cmaj7"} :4 12.6 r |

The second characteristic device is the major triads a minor 3rd apart. The half-whole scale from G contains the major triads on G, Bb, Db and E, and playing those four triads in sequence over a G7b9 produces the strongest diminished-dominant sound there is: each triad is consonant on its own, and the sequence outlines the whole scale. You already have the triad shapes from Theory I.

\tempo 126
.
\ts 4 4
:8 5.4{ch "G13b9"} 4.3 3.2 4.3 3.3 3.2 6.2 3.2 | 6.3 6.2 4.1 6.2 5.2 4.1 7.1 4.1 | :2 3.1{ch "Cmaj7"} 5.2 |

Whole-half diminished for dim7

Over a diminished seventh chord the same eight notes are played from the chord's root, so the first step is a whole step. Diminished seventh chords in standards are usually passing chords (I – #i°7 – ii, or the #IV°7 of a jazz blues) that last two beats, so the scale is less important than the arpeggio plus one or two of the whole-step upper notes. Where the scale does come into its own is on a tune that sits on a dim7 for a whole bar or more.

\tempo 100
.
\ts 4 4
:8 7.6{ch "Bdim7"} 9.6 10.6 7.5 8.5 10.5 6.4 8.4 | 9.4 6.3 7.3 9.3 10.3 8.2 9.2 6.1 | 7.1 9.1 10.1 9.1 7.1 6.1 9.2 8.2 | 10.3 9.3 7.3 6.3 9.4 8.4 6.4 10.5 | 8.5 7.5 10.6 9.6 :2 7.6 | :8 7.6 10.6 8.5 6.4 8.4 6.4 8.5 10.5 | 9.4 7.3 10.3 9.3 7.3 6.3 9.4 8.4 | :2 8.2{ch "Cmaj7"} :4 9.3 r |

Because B whole-half and G half-whole are one scale, everything you practise for 7b9 chords is automatically practised for dim7 chords a major 3rd above the dominant root, and the reverse. Learn each cell in both contexts.

Whole tone for 7#5

The whole-tone scale has only two forms, and each is two augmented triads a whole step apart. Over G7#5 (and G7b5, G9#5 and the augmented triad) it supplies the 9, the #11 and the #5 as colours around the 3rd and b7. There is no 5 and no b9, so it never sounds as dark as the diminished or altered scales; it sounds suspended, dreamy, slightly off balance.

\tempo 116
.
\ts 4 4
:8 3.6{ch "G7#5"} 5.6 2.5 4.5 6.5 3.4 5.4 2.3 | 4.3 6.3 4.2 6.2 3.1 5.1 3.1 6.2 | 4.2 6.3 4.3 2.3 5.4 3.4 6.5 4.5 | :2 2.5{ch "Cmaj7"} 3.1 |

The characteristic whole-tone patterns are the augmented triad (every other note of the scale), the "1 2 3" three-note cell moved up a whole step each time, and the major-3rd cell. Because the scale repeats every two frets, any cell on one string set can be moved up two frets indefinitely, which makes the whole-tone scale the easiest scale on the guitar to play all over the neck from a single shape.

A caution: the whole-tone scale announces itself after about four notes. Used for a bar on a 7#5 it is a beautiful colour; used for a chorus it becomes a cliché. Mix it with the altered scale, which shares the 3, #5 (b13), b7 and #11 of the whole-tone scale and adds the b9 and #9.

Choosing between the dominant scales

By now you have five scales for a dominant chord, and the choice is a matter of what the symbol and the resolution ask for:

• 7, 9, 13 (unaltered): Mixolydian; Lydian dominant if it does not resolve down a 5th.
• 7b9, 13b9, 7#9 with a natural 5 or 13: half-whole diminished.
• 7#5, 7b5, 9#5: whole tone.
• 7alt, 7b9b13, 7#9b13: altered scale.
• V7b9 in a minor key where you want to stay inside: Phrygian dominant.

In practice players mix them within a bar; what matters is that the long notes and the resolution match the symbol. The diminished scale's natural 13 and the altered scale's b13 are the clearest point of difference, and the one a rhythm section will notice.

Exercises

1. Three scales only. Play C, Db and D half-whole in position III. Every other diminished scale is one of these; name which, for all twelve roots.
2. Three-fret drill. Take any two-string cell from a diminished scale and move it up the neck in three-fret steps, then down. Do the same with a whole-tone cell in two-fret steps.
3. Cell invention. Write four of your own four-note diminished cells (any order of R b9 #9 3, or 3 #11 5 13) and play each in minor-3rd sequence over a G13b9 loop, resolving to Cmaj7.
4. Triads. Over each dominant chord in a ii–V–I in C, F, Bb and Eb, play the four major triads from its half-whole scale, then resolve. Then the two augmented triads from its whole-tone scale.
5. Dim7 in context. Over a jazz blues in F, play whole-half diminished on the #IV°7 bar only and chord tones everywhere else.

Quiz