Ascending °7 chord

One of the uses of a °7 chord is for it to behave like a secondary dominant.

An ascending diminished chord is a °7 chord that acts as a secondary dominant. It moves up a half step.1

Some things to note:

  • vii°7/IV (#IV°7) doesn't really work: it instead wants to move to I/5
  • ascending diminished chords should be placed on weak beats and resolve on strong beats

Example: C -> Am can be C -> G#°7 -> Am.

A cool gospel progression is:


| I    | #I°7   | IIm | #II°7 |
| IIIm | V7/IV  | IV  | #IV°7 |
| I/5  | #V°7   | IVm | V/V   |
| I/5  | V7sus4 | I   |