The diminished whole tone scale (aka super locrian scale, altered scale, altered dominant scale, Pomeroy scale) is nothing if not colorful. A mode of the ascending melodic minor scale built on that scale’s seventh degree, the diminished whole tone scale encompasses virtually every alteration to a dominant chord that you can think of: #5, b9, #9, and #11. It’s commonly used over dominant chords of various alterations, and is ideally suited to the V+7#9.
The name “diminished whole tone” refers to the scale’s two tetrachords. The bottom tetrachord derives from a half-whole diminished scale, and the top tetrachord suggests a whole tone scale. For example, connecting the tetrachord B, C, D, and Eb with the tetrachord F, G, A, and B will give you a B diminished whole tone scale: B, C, D, Eb, F, G, A, B. (In actual use, you’d want to think of the Eb enharmonically as a D#, the major third of a B+7#9 chord).
To your right is an exercise that will take you around the cycle of fifths with one of my favorite diminished whole tone licks. (Click on the thumbnail to enlarge it.) I like the lick for three reasons. It starts and finishes on the highly consonant major third of the altered dominant chord, but in between it spotlights the altered tones of the chord (#5, b9, #9). It emphasizes the half-step relationship between the third and #9, and between the b9 and the chord root. And it outlines the major triad built on the raised fifth of the altered dominant–e.g. the #5 of a D+7#9, A# (Bb enharmonically) gives rise to a Bb major triad.
Have fun with the exercise. If you’re not familiar with the diminished whole tone sound, it may take a while to get it into your ear, but you’ll be glad you did.
Look for more exercises, helpful articles, and solo transcriptions on my jazz page.
