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New Released in April 2026

C Sharp Diminished Chord on Piano (C#dim)

To play C#dim on the piano, press C#, E, G together. Start from C#m and move the fifth down a semitone: that one key turns it into C#dim. Here is where C#dim comes from, where it resolves and how to play it with both hands.

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  • MIDI keyboard
  • Digital or acoustic piano
  • Guitar
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C#dim C# E G

Four triads on C#

Same root, same third or fifth moved by a semitone.

ChordNotesThirdFifth
C# C# E# G#major 3rdperfect 5th
C#m C# E G#minor 3rdperfect 5th
C#dim C# E Gminor 3rddiminished 5th
C#aug C# E# G##major 3rdaugmented 5th

What C#dim does in music

  • C#dim is the vii° chord of D major and the ii° chord of B minor.
  • It wants to move up a semitone: C#dim → D / Dm, the bottom note rising to the new root.
  • Add B and you get C#m7b5 (half-diminished); add Bb instead and you get C#dim7 (diminished 7th).

C#m7b5 · D

The C sharp diminished chord and its inversions

Thumb, middle and little finger in the right hand: 1-3-5.

C#dim C# E G

Root position: C# E G

C#dim E G C#

1st inversion: E G C#

C#dim G C# E

2nd inversion: G C# E

  • Root position: starts on C#, a black key; black keys: C#
  • 1st inversion: starts on E, a white key; black keys: C#
  • 2nd inversion: starts on G, a white key; black keys: C#
ChordRunner showing a chord block while hands play the piano

Make C#dim automatic

In ChordRunner C#dim rides towards your runner between other chords: play it in time. MIDI keyboard or microphone, both work.

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All piano chords · Diminished chords explained

Common questions

What notes are in the C sharp diminished chord?

C#dim has three notes: C#, E, G. Root, minor 3rd and diminished 5th (formula 1 b3 b5).

What is the difference between C#dim and C#m?

One note. C#m has G# on top; C#dim moves it to G. The new fifth is what gives C#dim its tense sound.

Where does C#dim go?

C#dim is the vii° chord of D major and the ii° chord of B minor. It wants to move up a semitone: C#dim → D / Dm, the bottom note rising to the new root.

Can I practise C#dim with a MIDI keyboard or microphone?

Yes. ChordRunner detects a USB MIDI keyboard automatically and also hears an acoustic piano through the microphone. C#dim counts in any position, as long as C#, E, G sound together.

Your instrument is the controller.

ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.

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