What notes are in a C♯ half-diminished chord?

C♯ half-diminished contains four notes: C♯ (root), E (minor third), G (diminished fifth), and B (minor seventh).

How does C♯m7♭5 resolve?

In B minor: C♯m7♭5 → F♯7 → Bm. The C♯m7♭5 sets up the V chord (F♯7), which then resolves to the tonic Bm.

Is C♯ half-diminished the same as C♯ diminished?

No — different chords. C♯° (the triad) is C♯-E-G; C♯m7♭5 (the four-note chord) adds a minor 7th (B) on top. The half-diminished version is a stacked version of the diminished triad.

Where does C♯ half-diminished appear in jazz?

In every jazz standard in B minor — "Beautiful Love," "Solar," and many others use C♯m7♭5 as the standard iiø7 setup before resolving to F♯7 → Bm.

C# half-diminished chord — notes, intervals, and practice

C♯ half-diminished (C♯m7♭5 or C♯ø) — C♯, E, G, B — is the iiø7 of B minor. The chord drives the B-minor minor-key cadence and shows up constantly in any jazz tune in B minor, plus countless classical works in B minor or D major (where it's a chromatic colour).

Intervals

The C# half-diminished chord stacks two thirds on the root. Each interval and its size in semitones:

C#→Eminor 3rd3 semitones
E→Gminor 3rd3 semitones
G→Bmajor 3rd4 semitones

On the keyboard

Each note of the C# half-diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the C# half-diminished chord on a six-string guitar fretboard.

Common mistakes

C♯m7♭5 contains C♯ (the only sharp) plus three naturals: E, G, B. The seventh B is the chord's major third away from G — a wider interval than dim7 chords use. Replacing B with B♭ would produce C♯°7 (fully diminished); the half-diminished colour requires the minor 7th (B natural).

In context

C♯m7♭5 → F♯7 → Bm is the ii–V–i in B minor, used in every B-minor jazz standard and most classical B-minor cadences. The chord also appears in D major as a chromatic colour (the ii of the parallel minor borrowed into the major). Schubert uses these borrowings constantly in his late piano sonatas.

Drill it

The C# half-diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in a C♯ half-diminished chord?: C♯ half-diminished contains four notes: C♯ (root), E (minor third), G (diminished fifth), and B (minor seventh).
How does C♯m7♭5 resolve?: In B minor: C♯m7♭5 → F♯7 → Bm. The C♯m7♭5 sets up the V chord (F♯7), which then resolves to the tonic Bm.
Is C♯ half-diminished the same as C♯ diminished?: No — different chords. C♯° (the triad) is C♯-E-G; C♯m7♭5 (the four-note chord) adds a minor 7th (B) on top. The half-diminished version is a stacked version of the diminished triad.
Where does C♯ half-diminished appear in jazz?: In every jazz standard in B minor — "Beautiful Love," "Solar," and many others use C♯m7♭5 as the standard iiø7 setup before resolving to F♯7 → Bm.