What notes are in the C#m7b5 chord?

C#m7b5 is made of C#, E, G and B — the 1, b3, b5 and b7 degrees of a half diminished seventh chord built on C#.

What keys use the C#m7b5 chord?

Every note of C#m7b5 belongs to 2 keys: D Major (vii°), B Minor (ii°). The roman numeral is the scale degree the chord is rooted on.

How do you play C#m7b5 on guitar and piano?

This page shows C#m7b5 on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.

Is C#m7b5 the same as Dbm7b5?

Yes. C#m7b5 and Dbm7b5 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; C#m7b5 is the spelling this site treats as canonical.

Chord · C# Half-Diminished 7th (m7♭5)

C♯m7♭5 Chord

C♯m7♭5 is C#, E, G and B — the ii in a minor ii-V-i.

Hear it

C♯m7♭5 on every instrument

The same 4 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.

What C♯m7♭5 is made of

C# Half-Diminished 7th (m7♭5) (C# half-diminished 7th (m7♭5)) is built from the notes C#, E, G, B, with the interval pattern 1, b3, b5, b7. A common half-diminished 7th (m7♭5) chord across many styles.

Stack 1, b3, b5 and b7 on a root of C♯ and you get C#, E, G and B. That interval recipe is what makes the chord a half diminished seventh chord — move the same shape to another root and the character travels with it, which is why Cm7♭5 sounds like a transposed C♯m7♭5.

Half-Diminished 7th (m7♭5): The ii in a minor ii-V-i.

Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with C♯ rather than its enharmonic equivalent.

Keys that contain C♯m7♭5

All 4 notes sit inside the scale of 2 keys. The roman numeral marks the degree the chord is rooted on.

Major keys

D Majorrooted on the vii°

Minor keys

B Minorrooted on the ii°

Other chords on C♯

Same root, different colour.

C♯mC# Minor C♯dimC# Diminished C♯m6C# Minor 6th C♯m7C# Minor 7th C♯m(maj7)C# Minor-Major 7th C♯dim7C# Diminished 7th C♯m9C# Minor 9th C♯m/♭3C# Minor (1st Inversion)

The same half diminished seventh shape, moved

The identical interval recipe, built on other roots.

Cm7♭5C Half-Diminished 7th (m7♭5)Dm7♭5D Half-Diminished 7th (m7♭5)Em7♭5E Half-Diminished 7th (m7♭5)Fm7♭5F Half-Diminished 7th (m7♭5)Gm7♭5G Half-Diminished 7th (m7♭5)Am7♭5A Half-Diminished 7th (m7♭5)Bm7♭5B Half-Diminished 7th (m7♭5)F♯m7♭5F# Half-Diminished 7th (m7♭5)

Questions people ask about C#m7b5

What notes are in the C#m7b5 chord?: C#m7b5 is made of C#, E, G and B — the 1, b3, b5 and b7 degrees of a half diminished seventh chord built on C#.
What keys use the C#m7b5 chord?: Every note of C#m7b5 belongs to 2 keys: D Major (vii°), B Minor (ii°). The roman numeral is the scale degree the chord is rooted on.
How do you play C#m7b5 on guitar and piano?: This page shows C#m7b5 on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Is C#m7b5 the same as Dbm7b5?: Yes. C#m7b5 and Dbm7b5 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; C#m7b5 is the spelling this site treats as canonical.

Learn the theory behind it

Why C♯m7♭5 behaves the way it does — the guides that explain the chord instead of just spelling it.

Functional Harmony: Three Roles, One EngineDiminished chords are almost always doing a job. This explains which one.6 min read Cadences — The Four Ways a Phrase EndsWhere all that tension goes — how the chord resolves into the next one.4 min read Voice Leading — Hold What You Can, Move Only What You MustHalf-steps do the work here. Voice leading is how you find them.6 min read