| I | ♭III | ♭V | ♭♭VII |
|---|---|---|---|
| Root | Minor third | Diminished fifth | Diminished seventh |
| F# | A | C | F# |
The F# Diminished Seventh chord is composed of 4 notes :
These notes form a diminished seventh chord, creating maximum and symmetrical tension.
The dim7 chord is entirely symmetrical, each note separated by 1.5 tones (minor third).
Its extreme tension and ambiguity make it a powerful tool for modulations and dramatic passages.
The dim7 chord has special harmonic functions:
Jazz: chromatic passing and dominant substitution.
Classical music: leading tone diminished function (vii°7).
Tango: creates the characteristic dramatic tension.