G#m7b5 G# half-diminished seventh chord
- Notes
- G# B D F#
- Formula
- 1 b3 b5 b7
- Semitones
- 0 3 6 10 above the root
- Also written
- Abm7b5 (Ab Cb Ebb Gb)
- Other symbols
- G#ø7, G#ø, G#m7(b5), G#min7b5
G# to B is a minor third (3 semitones), B to D is a minor third (3 semitones), D to F# is a major third (4 semitones). A diminished triad plus a minor seventh, F#, so G# to D is a tritone. It is also called half-diminished: the fully diminished G#dim7 has a diminished seventh (9 semitones) instead. With B in the bass the same four keys read as Bm6.
G#m7b5 on the piano
Root position from G#4: G#4, B4, D5, F#5. Middle C is C4.
G#m7b5 on the guitar
Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has G# as its lowest note.
4 x 4 4 3 x (low E to high e)
Sounds G#2 F#3 B3 D4
x 11 12 11 12 x (low E to high e)
Sounds G#3 D4 F#4 B4
The E-shape and A-shape grips are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play half-diminished seventh chords on other roots.
Inversions of G#m7b5
An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | G# B D F# | G#m7b5 | |
| 1st inversion | B D F# G# | Bm6 (also read as G#m7b5/B) | |
| 2nd inversion | D F# G# B | G#m7b5/D | |
| 3rd inversion | F# G# B D | G#m7b5/F# |
Where G#m7b5 fits
G#m7b5 is viiø7 in A major, iiø7 in F# minor. As iiø7 it opens the minor ii–V–i: G#m7b5 → C#7 → F#m, the minor-key twin of the ii–V–I.