Diminished ( Whole - Half ) scale intervals question


(lettuce) #1

I want to correctly describe the intervals, counting up from the root note to each of the scale degrees in the diminished ( whole - half ) scale. This is what I have so far, I’m not so sure if its right.

C DIMINISHED [WHOLE - HALF] :

R W H W H W H W H

R M2 m3 P4 d5 m6 d7 M7 P8

1 2 b3 4 b5 b6 6 7 8

C D Eb F Gb Ab A B C

I used flats because the scale degrees have been flattened in the scale formula.

There are 8 notes in the scale before the octave so I cant describe the intervals just as intervals numbered 1-7 as usual.

There must be one double number. Also there is a double lettered note name ( ‘Ab’ AND ‘A’ ) which is unusual.

I went for ‘diminished 7th’ AND ‘Major 7th’.

Is that right?

Or should I have used ‘minor 6th’ AND ‘Major 6th’, onward to ‘Major 7th’ and ‘Perfect Octave’?

I have a feeling that might be the right way because there is a ‘b6’ AND a ‘6’ in the scale formula ( unusual because there are two 6th degrees of the scale ).


(radian) #2

Diminished 7 is the right name for the A in this case.

( If you were playingC°7chord the A would the 7th )


(lettuce) #3

Diminished whole-half scale.

Its a weird one.

I thought ‘A’ must be diminished 7th too, because 9 semitones is a diminished 7th interval and because ‘A’ is the seventh scale degree.

Naming ‘A’ as diminished 7th would lead to interval naming ( from root note to each scale degree ) including two ‘7’ intervals.

There must be two of some interval as diminished whole-half has 8 note before the octave instead of the usual 7 notes before the octave, as in the more traditional scales.

After some time had passed I looked back at the scale formula ( 1 2 b3 4 b5 b6 6 7 8 ) and noticed that there is both a ‘b6’ ( flattened sixth ) and and ‘6’ ( Normal / Major sixth ) so instead of using diminished 7th, I went with Major sixth. Diminished 7th and Major 6th intervals both have 9 semitones. After changing it it looks like this ( I put number of semitones in this time around, in the second row ):

R W H W H W H W H

0 2 3 5 6 8 9 11 12

R M2 m3 P4 d5 m6 M6 M7 P8

1 2 b3 4 b5 b6 6 7 8

C D Eb F Gb Ab A B C

I don’t know if there is any logic to it at all, but at some point in time classical people must have decided to ‘double up’ the sixth interval in diminished scales ( rather than any interval of their choosing ). This is my assumption based on looking at the scale formula.

They want to describe everything in terms of 7 scale degrees because it fits nicely with their traditional view of music ( the seven modes ).

As diminished has 8 scale degrees before the octave, rather than seven, it was probably considered to be devilish or something.

It does sound quite ‘vampiric’ like ‘transylvania’ or something like that.

I think you are right about describing the ‘A’ as a diminished 7th in the context of a C°7 chord. With diminished meaning ‘reduced by two semitones’. The seventh degree of C Major scale is B, reduced by two semitones to Bbb, B double flat ( which is an A ). Looking at that, it makes me think my scale formula may be wrong. I’m seriously confused by this.

c-diminished-7th-chord-intervals-on-pian