7th Chords
A Diminished 7th chord
Three stacked minor thirds. Maximum tension, fully symmetrical, and able to resolve in four directions.
Notes in A Diminished 7th
| Note | Interval | Semitones from root |
|---|---|---|
| A | Root | 0 |
| C | Minor 3rd | 3 |
| D# | Tritone | 6 |
| F# | Major 6th | 9 |
Formula: 0–3–6–9 semitones above the root. Move the whole shape up or down and you get the same chord in another key — that is why Diminished 7th chords sound alike no matter where they start.
Other chords on A
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