14.53Your diminished-chord toolkit

For now, you need four practical uses:

1. Leading tone

B°7 → C

2. Passing chord

C → C♯°7 → Dm

3. Dominant substitute/color

B°7 over G bass = G7♭9

4. Modulation pivot

Same °7 shape can be reinterpreted toward several destinations.

If you understand those four, diminished harmony has stopped being mysterious.