Chord · 7ths

Adim7 — A Diminished 7th

Adim7 is the A diminished 7th chord. It is built on the root A with minor 3rd (C), diminished 5th (E♭) and diminished 7th (G♭) above it — the formula 1 ♭3 ♭5 𝄫7, sounding the notes A C E♭ G♭. On the piano it sits at A (octave 3) and above in the library's voicing; the same 4 notes in any octave are still Adim7.

Root
A
Quality
Diminished 7th
Formula
1 ♭3 ♭5 𝄫7
Notes
A C E♭ G♭

On the keyboard

Adim7 on the piano keyboard: A C E♭ G♭1235ACE♭G♭

Right-hand fingering for this voicing: 1–2–3–5 (1 is the thumb).

The notes of Adim7

DegreeNoteInterval from the rootPitch
1ArootA3
♭3Cminor 3rdC4
♭5E♭diminished 5thE♭4
𝄫7G♭diminished 7thG♭4

Other 7ths on A

Diminished 7th chords on every root

Part of the chord reference. See also the scales and the keys.