A°7
Sevenths · A root
A°7
Maximum tension. Fully symmetric — every inversion sounds similar.
0 st3 st6 st9 st
Notes in A°7
ARoot
C3rd
D#5th
F#7th
A is the reference pitch (A440). Very common in rock and pop — the vi chord in C major.
Identify the Chord Quality on A
Each chord below is played on A. Listen and identify whether you heard A°7, Am, A7, or another quality — the hardest and most useful ear training skill.
Diminished 7th in All 12 Keys
Other Chords in A
Related Sevenths
About the A°7 Chord
The A°7 chord is a diminished 7th chord built on A. It contains the notes A, C, D#, F# — the root, third, fifth, and seventh.
Maximum tension. Fully symmetric — every inversion sounds similar. Practising the A°7 chord across different voicings and contexts builds the harmonic recognition that lets you identify it instantly in any musical setting — whether in a band mix, a recording, or a live performance.