18.4: Writing Secondary Diminished Chords
18.4 Writing Secondary Diminished Chords
To write a secondary diminished chord, use the following procedure.
-
First determine the note that is the root of the chord being tonicized (the chord to the right of the slash).
- Determine viivii∘7 in the key of C minor (C is the root of the iviv chord, which is the Roman numeral after the slash): B is the root of viivii∘7 in C minor because it is a m2 below C.
- Build a fully–diminished seventh chord on B: B–D–F–A ♭
-
Invert the chord accordingly. 24 inversion means the 7th of the chord (A♭) is the bass note.