About GmMaj7b5 — drop 2 voicings
GmMaj7b5 is G, Bb, Db and F# — Gm7b5 with the seventh raised a semitone.
It sounds brittle and impossible to mistake. Scarce enough that most players meet it as a passing sonority rather than as a chord they chose.
GmMaj7b5 notes and formula
| G | Bb | Db | F# |
|---|---|---|---|
| 1 | ♭3 | ♭5 | 7 |
Rare tonic — a half-diminished chord with its seventh raised instead.
Also written GmM7b5 or Gm(maj7)b5. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play GmMaj7b5
Take the four notes stacked as close together as they go, then drop the second voice from the top an octave. The gap it opens is what makes the chord sound like a chord rather than a cluster.
It lands on four adjacent strings, which is why it is the workhorse voicing on guitar.
GmMaj7b5 has 12 of them, on the top four strings, the bottom four strings and the middle four strings, from open position up to the 11th — every inversion the chord has: G in the bass, Bb in the bass, Db in the bass and F# in the bass. The one to learn first is the F# shape at the 2nd fret, which is the easiest grip here.
4 of them sit on the top four strings, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with xx5676 — no barre and low, at the 5th fret. None of the shapes for GmMaj7b5 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 2 of the 5 need a barre. Together they cover the neck from the 2nd fret to the 11th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 3443x3 | 3rd fret | G, root position | G | barred |
| 34x322 | 2nd fret | G, root position | F# | all fretted |
| xx5676 | 5th fret | G, root position | Bb | all fretted |
| x-10-x-11-11-9 | 9th fret | G, root position | Db | all fretted |
| x-10-11-11-11-x | 10th fret | G, root position | Bb | barred |
The same notes rebuilt from scratch give 3 shell and 9 drop 3 voicings, each on its own page.
Tensions. A shell of GmMaj7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the 11 (C) and the b13 (Eb).
What to play over GmMaj7b5
Every note of GmMaj7b5 is in G diminished.
Chords near GmMaj7b5
Change one note of GmMaj7b5 and you have Gdim (drop the major seventh), Gdim7 (the major seventh becomes a sixth), Gmaj7b5 (the minor third becomes a major third), Gm7b5 (the major seventh becomes a flat seventh) or GmMaj7 (the flat fifth becomes a fifth).
GmMaj7b5 is a diminished chord — root, minor third, flat fifth. Diminished and half-diminished chords on every root.
On GmMaj7b5’s sound and use this page follows Robert Rawlins & Nor Eddine Bahha, Jazzology (Hal Leonard, 2005). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.