Cdim 8-string guitar chord

How to play Cdim on 8-string guitar

The most common way, the first shape above: your index finger on the A string at the 3rd fret, your middle finger on the D string at the 4th fret, your little finger on the G string at the 5th fret and your ring finger on the high B string at the 4th fret. Don’t play the F♯, low B, low E and high E strings.

From the F♯ string x x x 3 4 5 4 x (x: not played, 0: open)

What notes are in Cdim?

Cdim, C diminished, is C, E♭ and G♭: the root (C), the minor third (E♭) and the diminished fifth (G♭). Its formula is 1 ♭3 ♭5.

What is the difference between Cdim, Cm7♭5 and Cdim7?

Cdim is three notes, C, E♭ and G♭. Cm7♭5 adds the minor seventh, B♭; Cdim7 adds the diminished seventh, B♭♭, a half step lower.

Where does Cdim go?

Most often up a half step, to D♭: it is the chord on the seventh note of a major key, leading back to the tonic.

Keys with Cdim

Cdim is the vii° chord in D♭ major and the ii° chord in B♭ minor.