Piano chord

C♯ Half-Diminished Chord

C♯m7♭5 is a half-diminished chord built on C♯. It contains the notes C♯ – E – G – B.

C♯m7♭5

Also written: C♯ø7, C♯ø, D♭m7♭5

E

G

B

C♯

Notes in C♯m7♭5

Count up from C♯ using the intervals below. The formula shows each note relative to the C♯ major scale.

Notes	Intervals	Formula	Semitones
C♯	Root	1	0
E	Minor 3rd	♭3	3
G	Diminished 5th	♭5	6
B	Minor 7th	♭7	10

Right hand: fingers 1–2–3–5 (thumb on C♯).
Left hand: fingers 5–3–2–1, or play just the root in the left hand and the other notes in the right.
Inversions keep your hand closer to the previous chord — see below.

An inversion puts a different note of C♯m7♭5 at the bottom. The notes stay the same, the colour and voice leading change.

Also called the half-diminished chord. The most melancholic chord in jazz — often used as the ii chord in minor key progressions.

Sound: Wistful & jazzy-dark

C♯m7♭5 is built only from notes of these keys. The Roman numeral shows its role in each key.

Hear C♯m7♭5 with different sounds and compare it with other chords in the interactive builder.

If chords sound sour even when you play the right notes, the piano is probably out of tune. Our technicians tune pianos across Israel.