The half-whole diminished scale on bass:
notes, formula and position

The half-whole diminished scale has 8 notes: 1 ♭2 ♭3 3 ♭5 5 6 ♭7. In A, that gives A, B♭, C, C♯, E♭, E, F♯ and G. Eight notes alternating half step and whole step: the scale of 7♭9 chords, much used in jazz and metal.

Also called: Diminished half/whole, dominant diminished scale, octatonic scale.

Formula and notes

1 ♭2 ♭3 3 ♭5 5 6 ♭7

The steps between the notes, from the root to the octave: half step – whole step – half step – whole step – half step – whole step – half step – whole step. In A:

One position on the neck

The half-whole diminished scale in A, in the 5th-fret position: one finger per fret, from the 4th to the 8th fret, on all four strings. The numbers are the degrees; the root is in gold.

The same position as bass tab (fret by fret, from the low E string to the G string):

G|-5--6--8-|
D|-4--5--7--8-|
A|-4--6--7-|
E|-5--6--8-|

For another key, move the whole shape: the root on the E string sets the key (3rd fret for G, 8th fret for C).

The sound of the half-whole diminished scale

Half-step/whole-step alternation. 8 notes. For 7♭9 chords. The dominant version: ♭9, ♯9, ♯11 and 13 in one scale. Repeats every 3 semitones.

You mostly hear it in jazz, metal and classical music.

Which chords to play it over

In A, the half-whole diminished scale fits A7♭9, A13♭9 and A7♯9. On bass, keep the root on the strong beats and use the other notes to connect the chords.

Practice it with UnitBasse

This diagram shows a single position, in a single key. In UnitBasse, this scale is shown across the whole neck and in all twelve keys, as note names, intervals or degrees, with one color per degree. You can listen to it, see the chords that go with it, switch keys in one click, and play it over a chord chart with BackTrack, the app’s backing band. The app has 69 scales in 12 families.

Frequently asked questions