The Diminished Scale is a symmetrical scale and alternates between a tone and a semitone. It's known as a Whole Half when played over Diminished 7th chords. Whole is referring to a Whole Tone and Half is half a Tone, which is better known as a semitone.

Scale Formula

The scale formula for the diminished scale easy to remember, just tone then semitone repeat! The formula describes the interval distances between each note of the scale.

	T		S		T		S		T		S		T		S
1		2		3		4		5		6		7		8		9

T = Tone [whole step] • S = Semitone [half step] • TS = Tone + Semitone (minor 3rd interval)

Comparison With Major Scale

Scales are usually compared to the Major Scale to find the intervals used, but because the Diminished Scale has 8 notes (Major Scale has only 7) it makes better sense to just look at it intervallically.

	I	II	III	IV	V	VI	VII	VIII	I
C Diminished Scale	C	D	Eb	F	Gb	G#	A	Bb	C
Equation	1	2	b3	4	b5	#5	6	b7	1
Chord Tones	1		b3		b5		bb7

You will see above that I have re-interpreted the intervals from a standard analysis to one that would show its use over Diminished 7th chords which are stacked minor 3rd intervals, so include the unusual bb7 degree which is particular to Diminished chords.

One fascinating thing about Diminished chords (and scales) is that the patterns move up and down 3 frets in either direction and the notes stay the same but change where they fall under the fingers.

Chords In The Key

Looking at the chords from the scale is a lot less useful than in diatonic context (the 7 note scales) although advanced players might enjoy figuring out how many chords they can derive from this collection of notes, it's a fun exercise if nothing else!

Further Reading

If you are studying this scale I would hope you are beyond the need for my Practical Music Theory course but if you're still struggling with chord construction and remembering the notes in your scales it might help!