The C diminished seventh chord (abbreviated "Cdim7 chord") is a four-note chord consisting of the notes C, E, G, and B. The chord is formed by adding a diminished seventh to a C diminished chord.

Name
C diminished seventh chord
Synonym
C fully diminished chord
Notes
C E G B
Intervals
1 3 5 7
Chord symbol
Co7
Alternative symbols
Cdim7 Cdim Co
Type
Tetrad (four-note chord)

Cdim7 chord on piano

Cdim7 chord on guitar

Cdim7 chord on ukulele

Cdim7 chord on the staff