A diminished seventh (Adim7) chord on piano

Diminished seventh chord (three stacked minor thirds) on A: the notes of the Adim7 chord are A – C – E♭ – G♭.

Root position: A3 – C4 – E♭4 – G♭4

What the Adim7 chord sounds like

A diminished seventh is three stacked minor thirds, so it is symmetrical: four different roots give the same notes. A dramatic, tense passing chord.

Notes of the Adim7 chord

Degree	Note	Interval from the root
1	A	root
3	C	minor third (3 semitones)
5	E♭	diminished fifth (6 semitones)
7	G♭	diminished seventh (9 semitones)

Root position and inversions

An inversion uses the same notes, with a different note at the bottom. When you change chords, choosing the nearest inversion keeps your hand almost still.

Root position

A3 – C4 – E♭4 – G♭4

1st inversion

C4 – E♭4 – G♭4 – A4

2nd inversion

E♭4 – G♭4 – A4 – C5

3rd inversion

G♭4 – A4 – C5 – E♭5

Which keys is it in?

The Adim7 chord is built from the notes of these keys (for minor keys, both the natural and the harmonic minor are considered):

B♭ minor: vii°7

Similar chords and substitutes

If Adim7 is too hard, or you want a different colour in the same spot, these chords are worth a try.

Substitutes (by function)

F7 – an incomplete dominant: the diminished chord is the top of this seventh chord
B♭ – where it leads (leading tone → root)

Same notes

Cdim7 – the same notes with a different root
E♭dim7 – the same notes with a different root
F♯dim7 – the same notes with a different root

Simpler versions

Adim – all 3 of its notes are in this chord

Frequently asked questions

What notes are in the Adim7 chord?

A, C, E♭, G♭. The root is A; the intervals of the other notes from the root: minor third, diminished fifth, diminished seventh.

How do I play the Adim7 chord on piano?

In root position, the right hand usually plays with fingers 1, 3 and 5 (thumb, middle finger, little finger); four-note chords with fingers 1, 2, 3 and 5. The left hand mirrors this: 5, 3, 1. In an inversion the top or bottom note moves to the other side, so your hand moves less when you change chords.

How is the Adim7 chord written?

The chord symbol is Adim7, and its full name is A diminished seventh.