Adim7 guitar chord
An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful.
- Tap a note to hear it
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About Adim7 — open string voicings
Adim7 is A, C, Eb and Gb — Adim with a diminished seventh stacked on top.
It sounds suspenseful and rootless. Three stacked minor thirds divide the octave evenly, so the same four notes spell four dim7 chords and the shape repeats every three frets.
Adim7 notes and formula
| A | C | Eb | Gb |
|---|---|---|---|
| 1 | ♭3 | ♭5 | ♭♭7 |
Leading-tone or passing chord — it can resolve almost anywhere.
Also written A°7, Ao7 or A diminished 7. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Adim7
An open string left ringing against a fretted grip. It costs no finger, so it can sound a note the closed shape has none left for: a tension on top, or a pedal root underneath.
These belong to their key rather than to a shape: they cannot be moved up the neck. D, A, G and E have many; E♭ has a handful.
Adim7 has 1 of them, only on strings 6-5-4-3-2, all of them at the 4th fret — all in one inversion, so the bass note never moves. The one to learn first is the A shape at the 4th fret, which is the easiest grip here.
Start with x01212 — no barre and 1 open string. 1 of the 8 shapes here sits in open position. 2 of the 8 need a barre. Together they cover the neck from the 1st fret to the 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x01212 | open position | A, root position | Gb | 1 open string |
| xx1212 | 1st fret | Eb, 2nd inversion | Gb | all fretted |
| 5x4545 | 4th fret | A, root position | A | barred |
| 567575 | 5th fret | A, root position | A | barred |
| xx7878 | 7th fret | A, root position | C | all fretted |
| x-x-10-11-10-11 | 10th fret | C, 1st inversion | Eb | all fretted |
| x-12-13-11-13-11 | 11th fret | A, root position | Eb | all fretted |
| x-x-13-14-13-14 | 13th fret | Eb, 2nd inversion | Gb | all fretted |
The same notes rebuilt from scratch give 5 shell, 14 drop 2 and 9 drop 3 voicings, each on its own page.
Tensions. A shell of Adim7, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (B), the 11 (D), the b13 (F) and the maj7 (G#).
How to use Adim7
A diminished seventh divides the octave evenly, so Adim7 has no single root and no single destination: it can lead to D or to Bb, and it is the same four notes either way.
What to play over Adim7
Every note of Adim7 is in A diminished and A half-whole diminished.
Chords near Adim7
Change one note of Adim7 and you have Adim (drop the sixth), Am6 (the flat fifth becomes a fifth), Am7b5 (the sixth becomes a flat seventh), AmMaj7b5 (the sixth becomes a major seventh) or Am/F# (the flat fifth becomes a fifth).
Adim7 is a diminished chord — root, minor third, flat fifth. Diminished and half-diminished chords on every root.
On Adim7’s sound and use this page follows Stefan Kostka, Dorothy Payne & Byron Almén, Tonal Harmony (McGraw-Hill, 8th ed., 2018). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.