C♯dim7

C♯1E♭3G♭5B♭♭♭7

Three minor thirds stacked. The seventh is doubly diminished, which is why it is written with a double flat.

Written the other way round it is D♭dim7 — the same twelve keys on a piano, a different piece of notation.

on guitar on piano the scale

What is true of it

C♯dim7 is C♯, E, G and B♭ — 1, b3, b5 and bb7 counted from C♯.

The easiest of the 1 fingering below is 6767: 3 fingers, one of them barring the 6th fret, held at the 6th fret.

None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.

Where its notes are on the neck

Fig. 3 — first 12 frets

The brass dots are C♯, the root. Everything else is a chord tone with its degree printed in it.

With a different note underneath

first inversion

C♯dim7/E

9a9a

second inversion

C♯dim7/G

0101

third inversion

C♯dim7/B♭

3434

An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.

C♯ in other shapes

C♯7dominant seventh C♯maj7major seventh C♯m7minor seventh C♯major C♯mminor C♯dimdiminished

Cdim7 Ddim7 D♯dim7 E♭dim7 Edim7 Fdim7 F♯dim7 G♭dim7 all 374