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

The bebop half-diminished scale has 8 notes: 1 ♭2 2 ♭3 4 ♭5 ♭6 ♭7. In A, that gives A, B♭, B, C, D, E♭, F and G. Locrian plus a passing note: a bebop scale for the m7♭5 chord.

Also called: Half-diminished bebop, Locrian bebop.

Formula and notes

1 ♭2 2 ♭3 4 ♭5 ♭6 ♭7

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

One position on the neck

The bebop half-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|-4--5--7--8-|
D|-5--7--8-|
A|-5--6--8-|
E|-5--6--7--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 bebop half-diminished scale

Locrian ♮2 + chromatic note. 8 notes. For m7♭5 chords in minor ii-V-I progressions.

You mostly hear it in jazz.

Which chords to play it over

In A, the bebop half-diminished scale fits Am7♭5. 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