Music Theory for the 21st-Century Classroom

Section 18.4 Writing Secondary Diminished Chords

1. 🔗

   First determine the note that is the root of the chord being tonicized (the chord to the right of the slash).
   
2. 🔗

   Determine ${\text{vii}}^{\circ }{}^7$ in the key of C minor (C is the root of the $\text{iv}$ chord, which is the Roman numeral after the slash): B is the root of ${\text{vii}}^{\circ }{}^7$ in C minor because it is a m2 below C.
3. 🔗

   Build a fully–diminished seventh chord on B: B–D–F–A♭
4. 🔗

   Invert the chord accordingly. ${}_2^4$ inversion means the 7th of the chord (A♭) is the bass note.