Cdim7 8-string guitar chord

How to play Cdim7 on 8-string guitar

The most common way, the first shape above: your index finger on the low B string at the 1st fret, your ring finger on the low E string at the 2nd fret, your middle finger on the D string at the 1st fret and your little finger on the G string at the 2nd fret. Let the A string ring open. Don’t play the F♯, high B and high E strings.

From the F♯ string x 1 2 0 1 2 x x (x: not played, 0: open)

What notes are in Cdim7?

Cdim7, C diminished seventh, is C, E♭, G♭ and B♭♭: the root (C), the minor third (E♭), the diminished fifth (G♭) and the diminished seventh (B♭♭). Its formula is 1 ♭3 ♭5 ♭♭7.

Why do four diminished seventh chords have the same notes?

A diminished seventh is minor thirds stacked all the way round, C, E♭, G♭ and B♭♭, so Cdim7 has the same notes as the diminished sevenths on E♭, G♭ and B♭♭. Any of its notes can be the root.