Eight notes alternating whole steps and half steps, beginning with a whole step. It is a rotation of the half-whole form, and there are likewise only three distinct forms.
1 = Bb
2 = C
b3 = Db
4 = Eb
b5 = Fb
b6 = Gb
6 = G
7 = A
Root
Bb (also written A#)
Scale
Diminished (whole-half)
Type
symmetric
Notes
Bb C Db Eb Fb Gb G A
Notes in the scale
8
Degree formula
1 2 b3 4 b5 b6 6 7
Semitones from the root
0 2 3 5 6 8 9 11
Step pattern
W H W H W H W H
Aliases
Octatonic W-H, Whole-half diminished
Key signature of this root
Bb major / G minor · Bb Eb
Written use
Named 1 2 b3 4 b5 b6 6 7. The natural scale over a diminished seventh chord, and a source of tension over a dominant chord with altered upper extensions.
Notes and degrees
Each degree of the scale, its note name in this key, and its distance from the root in semitones.
Degree
Note
Semitones
Interval from the root
1
Bb
0
Perfect unison
tonic
2
C
2
Major second
b3
Db
3
Minor third
4
Eb
5
Perfect fourth
b5
Fb
6
Tritone
b6
Gb
8
Minor sixth
6
G
9
Major sixth
7
A
11
Major seventh
Positions on the guitar
The five windows below are computed, not copied from a shape chart. The script locates the lowest
occurrence of Bb on each of the five upper strings within the first twelve frets and takes a
five-fret window centred on it. Because a scale repeats every twelve frets, these five windows cover
the whole neck; the same sequence returns an octave higher. The positions are numbered from the lowest
fret upwards, so position 1 is always the window nearest the nut and position 5 the window nearest the
twelfth fret.
Position 1 — frets 0–3
Root on the 5th string A2 at fret 1. 16 notes of the scale inside this window.
Read the grid as a chord diagram: the top row is the first string. Degrees appear in the
notes and degrees table above; a filled cell is a note of the scale, and the shaded cell is the tonic.