Diminished scales aternate between half steps and whole steps.
There are only 2 modes in this family — the scale that begins with a whole step is called a diminished or diminished (whole-step) scale:
C diminished scale:
C D Eb F Gb Ab A B C
If you begin with a half step, the resultant sale is called an inverted diminished or diminished (half step) scale:
C Db Eb E F# G A Bb C
Because of their symmetrial alternatin of half and whole steps, any diminished mode starting on C, Eb, Gb or A will contain the same pitches (or their enharmonical equivalent). Likewise the D, F, Ab and B diminished modes as well as the Db, E, G and Bb diminisehd modes, all have the same pitches in common.
C dim = Eb dim = Gb dim = A dim
The diminished scale is used when improvising on diminished traids, fully diminished 7th chords, diminshed/major 7th chords and a bitonal chord whose upper extensions form a triad a half step below the root of the chord.
Although a couple of the scle tones clash with the chord, the dim scale may also be used with discretion over min 7th and half dim 7th chords, esp when they resolve to an altered dom 7th chord in the context of a ii-V progression.
Dim traids consists of a root, a minor 3rd and a dim 5th.
A fully diminished 7th chord — is a diminished triad with a diminished (doubly flatted) 7th added and a dim/major7th chord consists of a diminisehd triad with a major7th added.
Dim chords usually function as passing chords between more stable sonorities.
All the notes in the dim scale work well over the dim th chord with the:
–2nd, 4th, b6th & M7 having the most color
The inverted dim scale is used when improvising over a dom7th chord with a b9, #9 or b5 — pariticularly when the chord is functioning as a V chord in a major key. In minor keys, V chords are best colored by the altered scale.
The inverted dim scale also may be used over two bitonal chords, one formed from a triad a dim 5th above the root and another formed by a raid a maj6th above the root.
The dom 7th b5 chord consists of a root, a major 3rd, a dim 5th and a min 7th.
A dom 7#11 chord consists of a dom 7 chord with an aug 11th added.
Adding a min 9 to a dom 7 chord creates a dom 7 b9 chord
dom 7 #9 chord consists of a dom 7 with an aug 9th
All the notes in the inverted dim scale work well over the altered om chords: the melodic use of the #9 and b9th high characteristic of bebop and post – bop styles.