Chord · Triads

Adim — A Diminished

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

Root
A
Quality
Diminished
Formula
1 ♭3 ♭5
Notes
A C E♭

On the keyboard

Adim on the piano keyboard: A C E♭135ACE♭

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

The notes of Adim

DegreeNoteInterval from the rootPitch
1ArootA3
♭3Cminor 3rdC4
♭5E♭diminished 5thE♭4

Other triads on A

Diminished chords on every root

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