C♯m7♭5

C♯1E♭3G♭5B♭7

A diminished triad with a minor seventh rather than a diminished one — half diminished, and not the same chord as dim7.

Written the other way round it is D♭m7♭5 — the same twelve keys on a piano, a different piece of notation.

on guitar on piano the scale

What is true of it

C♯m7♭5 is C♯, E, G and B — 1, b3, b5 and b7 counted from C♯.

These are also the notes of Em6/C♯. Which name is right depends on what is underneath and what came before — the notes alone do not decide.

The easiest of the 1 fingering below is 6777: 4 fingers, 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♯m7♭5/E

9b9a

second inversion

C♯m7♭5/G

0102

third inversion

C♯m7♭5/B

4704

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

Cm7♭5 Dm7♭5 D♯m7♭5 E♭m7♭5 Em7♭5 Fm7♭5 F♯m7♭5 G♭m7♭5 all 374