C#dim7

General info

Full name

C# Diminished 7th

Symbol

C#dim7

Root

C#

Quality

Diminished 7th

Chord notes

Functions & resolutions

Stability / tension

Maximum tension — extremely unstable

Most common resolutions

DD MajorFF Major

Unstable degrees

2D#

b3E

resolves down to the 2nd

4F#

b5G

resolves inward to the 4th

b6A

bb7A#

resolves down to the tonic 5th

Main resolution

C#dim7source

DD Major

Diminished C#dim acts as a leading-tone chord — resolves up a half step to D. All tones are unstable, moving by semitones inward and outward to stable degrees.

Other resolutions

C#dim7source

Deceptive resolution

FF Major

Due to its symmetry, a diminished 7th chord can resolve to any major or minor chord a minor 3rd apart.

C#dim7source

Modal resolution

D#mD# Minor

In modal context, a diminished chord can be used as a passing chord, connecting two diatonic chords through chromatic bass motion.

C#dim7source

Jazz reharmonization

C7C Dominant 7

In jazz, dim7 is often reinterpreted as a rootless dominant 7b9. For example, C#dim7 ≈ C7b9, opening additional resolution paths.

C#dim7source

Functional resolution

G#mG# Minor

A diminished chord can function as a leading-tone chord to any degree — not just the tonic. Often used before the ii, iii, or vi degrees.

Features

Character

Fully diminished, symmetric and unstable

Characteristic interval

Diminished 7th (°7)

Description

Four tones are stacked in minor 3rds; the diminished 5th and 7th create two tritones. Symmetry allows any tone to be enharmonically reinterpreted as the root.

Application

• Leading-tone seventh in minor
• Secondary leading-tone chords
• Chromatic voice leading

Voicing & structure

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.