I: A Brief Introduction to the Diminished Scale
The symmetrical diminished scale is an 8-note scale comprised of a repeating intervallic pattern. There are two forms of the symmetrical diminished scale: the half-whole (H/W) and whole-half (W/H) diminished scale.
Formulas (in relation to the root of the scale):
Half-Whole: 1-b2-#2-3-#4-5-6-b7
Whole-Half: 1-2-b3-4-b5-b6-6-7
Scales from a “C” root:
Half-Whole: C-Db-Eb-E-F#-G-A-Bb
Whole-Half: C-D-Eb-F-Gb-Ab-A-B
Notice the repeating intervallic patterns:
Half-Whole: C to Db is a half step. Db to Eb is a whole step, Eb to E is a half step. E to F# is a whole step and so on.
Whole-Half: C to D is a whole step. D to Eb is a half step. Eb to F is a whole step. F to Gb is a half step and so on.
The next thing to know is that there are only 3 “families” of the diminished scale. Due to this scales symmetrical nature any given diminished scale can be used over 4 diminished chords. That’s right, the same exact scale can be used on 4 different diminished chords a minor 3rd apart. For example, if you are using a C whole-half diminished scale on a C dim7 chord you can use the same exact scale on Eb dim7, Gb dim7 and A dim7 as they are the same chord as C dim7. These three “families” are listed below
Family 1: C, Eb, Gb and A
Family 2: C#, E, G and Bb
Family 3: B, D, F and G#
Before learning the following superimpositions of this symmetrical diminished scale it is highly recommended that you are extremely familiar with the mechanics and inner workings of the scale. You can accomplish this by doing some or all of the following:
• Learn the diminished scale in all three families on the entire fretboard (diagrams have been provided). When you look at these diagrams you will notice that if you are using a C W/H and you start it from the 2nd degree you get a D H/W. If you are using a C H/W and you start it from the 2nd degree you get a Db W/H. Basically if you know the names of the notes contained in your starting scale and you just alternate the W/H and H/W shapes every time you move to the next scale degree you can work out the whole fretboard.
• Sequence various intervals diatonically through the scales at various tempos and time signatures.
II: Diminished 7 Chords
The most obvious use for either of these diminished scales is on a diminished 7 chord. The most common scale used over a diminished 7 chord is the whole-half diminished which is an 8 note scale constructed by alternating whole steps and half steps.
Why it works: the W/H scale over a diminished 7 chord works well because it contains the four notes of the diminished chord it is being used on as well as four passing tones (which form another diminished 7 chord a whole step above the root of the one you are soloing on). These passing tones are also used as tensions 9, 11, b13 and natural 7.
Example: To solo on C°7 you could use a C W/H which contains the following notes:
C-D-Eb-F-Gb-Ab-A-B
The highlighted notes are the chord tones of the C°7 chord (C, Eb, Gb and A) while the remaining notes (D, F, Ab and B) form a D°7 chord and contains the tensions 9, 11, b13 and natural 7 when related to the root of C.
As mentioned before you can use the same diminished scale on 4 different diminished chords a minor third apart. In the above example you can use the same exact C W/H scale to solo on C°7, Eb°7, Gb°7 and A°7.
How to practice: Improvise using the W/H diminished scale on a static °7 vamp at various tempos, time signatures and styles. First start out in a single position, then keep adding positions one at a time until you are using the whole fretboard. Also, try to create melodies on single strings. Utilize the sequenced intervals that you worked out in your lines. Be sure to practice at slow tempos (less then 60 BPM) as this will allow you to develop great control of your instrument and the scale.
III: Tension Resolution
Before we get into the other uses of diminished 7 chords it is extremely important to understand the principle of tension resolution. Personally, I believe that you can play any of the 12 notes over any chord. Every single note is available to you. There are no “wrong” notes, you just have to know how to resolve them.
In an improvisational setting you are presented with chord changes and expected to solo over them. To achieve this we typically use chord scales. Most chord scales contain two things: the notes of the underlying harmony and other notes called “tensions”. The notes of the underlying harmony are your “safe” notes. They are firm grounding that you can always revert back to. Tensions are notes that add color to the chord and sound the function of the chord. Some tensions sound great and some sound a little out there. It is important to know where each tension resolves in order to create strong sounding lines.
Here is a chart of common resolutions of tensions. It is important to note that some tensions have more then one resolution possibility and others, namely the altered tensions, only have one.
b9: resolves down half step to root
9: resolves up to 3 (or b3 in minor) or down a whole step to the root
#9: resolves up a half step to third.
11: resolves to 3 (or b3 in minor) or up to 5th (or b5 on -7b5 or °7 chords)
#11: resolves up a half step to the 5th
b13: resolves down a half step to the 5th 13: resolves to the 5th or 7th
*note: that the 13th or b13th is typically an avoid note on minor chords but still can sound great if these concepts are applied.
*note: these are just suggestions they are not concrete. Some times the music calls for the tension to not be resolved. Use your ear.
IV: Dominant 7 Chords
Another very common use is to superimpose a H/W scale from the root of a dominant 7 chord.
Why it works: A diminished 7 chord contains the same notes as a dominant 7 b9 chord with out the root of the dominant 7 b9 chord.
C°7= C-Eb-Gb-A
B7b9: B-C-D# (Eb)-F#(Gb)-A
This also means that you can play the same diminished scale over 4 different dominant chords a minor 3 apart. If you are using C H/W over C7 you can play the same scale on Eb7, Gb7 and A7.
Tensions: If you were to play a C H/W over a C7 chord you would get the following notes:
C-Db-Eb-E-F#-G-A-Bb
As you can see by the highlighted notes, this scale contains the chord tones of the C7 chord. It also contains tensions b9, #9, #11 and 13.
How to practice: Put on a static dominant 7 chord. Solo with the chord tones only first. Then add a single tension that comes from the H/W scale from the root of that dominant 7 chord (for example, b9). Practice resolving this tension using the guidelines on tension resolution mentioned earlier. Do this for all of the tensions individually. Combine all of the tensions and vary tempo, style and time signature. Once you are comfortable using the scale over a static chord apply it to a II-V progression or a tune you are working on.
V: Major 7 Chords
On a major 7 chord you can superimpose a W/H diminished from the root, b9 and 2. By doing this you unlock all 12 tones and this is where tension resolution becomes very important.
Why it works: Examples over C major 7
C W/H: C-D-Eb-F-Gb-Ab-A-B
Db W/H: Db-Eb-E-Gb-G-A-Bb-C
D W/H: D-E-F-G-Ab-Bb-B-C#
The highlighted notes are the chord tones and available diatonic tensions that are contained in each of the possible superimpositions. As you can see each scale contains 4 notes that can be classified as either chord tones or available diatonic tensions while the other 4 notes are altered tensions or the 11th (which is technically an avoid note over a major 7 chord but can be used if resolved properly and properly placed within the phrase). The highlighted pitches supply the diatonic notes that can effectively describe the chord quality and function while also containing “outside” notes that are to be resolved to the diatonic notes.
*note: typically an improviser will use one superimposition at a time and usually switch which superimposition they use each chorus or appearance of a major 7 chord. However, nothing is stopping you from using 2 or all 3 at the same time (it can sound really cool!).
Tensions: here are the tensions that each superimposition gives you:
W/H from root: 9, #9, 11, b13, 13
W/H from 2: 9, 11, b13, b7, b9
The highlighted notes are altered tensions and “avoid” notes. As you can see each scale contains a fair amount of “outside” notes making tensions resolution an important part of this concept. Due to the restful nature of major 7th chords this concept can really create some “out” sounding lines that stretch the ear of the player and the listener.
How to practice: Put on a static major 7 chord. Solo with the chord tones only first. Pick a single superimposition scale and then work on resolving each tension individually and then combined. Repeat this process for the other superimpositions. Play in all 12 keys, at various tempos, time signatures and styles. Next, apply these concepts to a II-V or a tune you are working on.
In the example lines provided in this lesson you will find that I have note provided any lines specifically labeled for use on a major 7 chord. This is because all eight of the lines I have composed for this lesson can be tailored to fit a major 7 chord. By “tailored” I mean that the notes can be changed to emphasize the chord tones and diatonic tensions and properly resolving the outside pitches either directly (meaning the next note played after the tension is the note of resolution) or indirectly (where the altered pitch is resolved later in the phrase. Additional notes are played in between the tension and the resolution).
Also, you may have noticed that I did not cover minor 7 chord and minor 7b5 chords in this lesson. This is part one of two. In the second part I will cover the concept of harmonic generalization (which will cover minor 7 and minor 7b5 chords) as well as deriving and using triad pairs, seventh chord pairs and hexatonics from the symmetrical diminished scale. I hope you enjoyed this lesson!
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