Adim A diminished chord
- Notes
- A C Eb
- Formula
- 1 b3 b5
- Semitones
- 0 3 6 above the root
- Other symbols
- A°, Am(b5)
A to C is a minor third (3 semitones), C to Eb is a minor third (3 semitones). Two minor thirds stacked, so A to Eb is a tritone (6 semitones) instead of a perfect fifth. The four-note Adim7 and Am7b5 grow from it by adding a note on top.
Adim on the piano
Root position from A4: A4, C5, Eb5. Middle C is C4.
Adim 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 A as its lowest note.
x 0 1 2 1 x (low E to high e)
Sounds A2 Eb3 A3 C4
5 6 7 5 x x (low E to high e)
Sounds A2 Eb3 A3 C4
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 diminished chords on other roots.
Adim on the ukulele
Standard ukulele tuning is G C E A, drawn with the G string on the left and frets downwards, as ukulele chord charts show it. The G string is tuned higher than the C string (G4 above middle C, a fifth over C4), so the lowest note you hear is usually on the C or E string, not on the G string, and a shape can sound as an inversion even when its root is on the G string. All four strings are strummed, so every string plays a chord tone; the root is in blue-green.
5350 (G C E A)
Sounds C5 Eb4 A4 A4
Lowest note Eb4, so the chord finder reads it as Adim/Eb (second inversion).
8080 (G C E A)
Sounds Eb5 C4 C5 A4
Lowest note C4, so the chord finder reads it as Adim/C (first inversion).
Inversions of Adim
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 | A C Eb | Adim | |
| 1st inversion | C Eb A | Adim/C | |
| 2nd inversion | Eb A C | Adim/Eb |
Where Adim fits
Adim is vii° in Bb major, ii° in G minor, vii° in Bb minor. Its root A is the leading tone of Bb: a half step below the tonic, so the chord usually moves up to it.