Last issue, we took a look at the dominant, or half-whole tone diminished scale. Diminished scales contain eight notes per octave, unlike the diatonic major and minor scales most commonly used in western music. This octatonic scale is derived from a pattern of half and whole steps, the distance of one or two frets apart on the guitar. Diminished scales can start with a half followed by a whole step, or a whole followed by a half step before arriving at the tonic again. These two octatonic patterns have different applications.
The diminished scale is used in jazz to solo over dominant seventh chords and their extensions (for example, b9, #9 and 13). The reason this works is because these chords are often built of minor third intervals, and the diminished scale contains four minor third intervals per octave. The dominant diminished or half-whole diminished scale contains both a major and minor third, making it perfect for use over dominant chords, as they contain a major third and flat seven. The whole-half diminished scale doesn’t contain a major third, but it still works when writing riffs, especially if you make use of the two tritones – they are perfect for riffs that require tension. I want to focus on its use as a technical exercise, and how it can be used to write riffs that sound darker and tenser than what can be derived from the major scale and its modes.
Exercise #1 outlines an ascending one-octave pattern of the whole-half tone diminished scale starting on G. I believe position shifts are crucial in getting this scale under your fingers fast. On the A string, I shift up a position with my first finger between the C natural and C sharp. I also shift with my first finger on the D string, between the F sharp and G natural. The second position shift isn’t necessary in the one-octave pattern, but this will make it easier to transition into the two-octave pattern. This helps keep the pattern linear and easy to remember. Whenever I have a new pattern to memorise, I also play the pattern chromatically up and down the neck. Start with a slow tempo and push it up until you can no longer play it cleanly, then you will know your target tempo. Every time you practise, try to push yourself a little past this speed. Over time, you should see an improvement in your playing.
Exercise two outlines an ascending and descending two-octave pattern of the whole-half tone diminished scale. I have added an anacrusis, or pick-up note, which is also a position shift. As you play across the strings, shift up one position with your first finger each time you change strings – except for the change between the G and B strings. To play the two-octave pattern, I use my second and third fingers to play the F# and G natural. This will make it faster when you descend. If you want to continue up an octave, then follow the same first-finger position shift pattern and slide up on the high E string. At speed, this pattern is a great warm-up exercise. Try building up speed on the first bar until you have it well and truly under your fingers, then play the pattern as it is written.
The best thing about diminished scales is that you can repeat the same pattern a minor third higher or lower, and you will get the same notes appearing in a different order. Exercise #3 outlines a one-bar pattern that shifts up a minor third every two beats. This 16th note pattern flies by at 120 beats per minute (BPM), but it is a great technical exercise and very useful when you write a riff using the dominant diminished scale. Come up with your own riffs or technical patterns, and see how they sound when you shift them up or down by minor thirds. Hopefully you can see the potential of this octatonic scale in adding a non-diatonic aspect to your playing.