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Guitar chords · Half-diminished 7th

C♯m7♭5 chord on guitar (C#m7b5)

C♯m7♭5 (C♯ 7th) has four notes: C♯, E, G and B, the , ♭3, ♭5 and ♭7.

Shapes

How to play C♯m7♭5

Strum a shape to hear it, or pick it one string at a time. R marks the ; the other numbers are the chord tones.

C♯m7♭5 has no common . Play it as the A shape at 4 or the E shape at fret 9. A keeps its fingering anywhere on the neck: slide it up or down and the , on the lowest played string, names the chord.

  • A shape · fret 4

    4fr××R♭5♭7♭3C♯GBE
  • E shape · fret 9

    8fr××R♭7♭3♭5C♯BEG
Name a shape you're holding: the chord finder

Notes and formula

What makes C♯m7♭5 half-diminished 7th

A is a with a minor 7th added, also written ø7. It is the vii chord of a major key with sevenths, and the ii chord of a minor key, where it leads into V in a minor ii–V–i.

  • 1Root: the note the chord is named after. Keep it.
  • 3Essential: makes the chord what it is. Never drop it.
  • 5Optional: drop it first when you run out of fingers.

The ♭3rd, the ♭5th and the ♭7th make C♯m7♭5 a .

  1. C♯Rroot
  2. E♭3essential
  3. G♭5essential
  4. B♭7essential
EADGBE0135791215C♯C♯C♯C♯C♯C♯C♯EGBEGBEGBEGBEGBEGBEGBEGBEG
  • C♯, the root
  • Other chord tones

C♯m7♭5 usually leads to F♯7 and then Bm: the iiø7–V7–i of B minor.

C♯m7♭5 and D♭m7♭5 are the same chord with two names: same , same sound. Which one you see depends on the key the song is written in.

Keys

Keys with C♯m7♭5

C♯m7♭5 belongs to two keys: D major (viiø7) and B minor (iiø7).

Numerals follow the key's own scale, so III, VI and VII in a minor key are its own major chords. A ♭ or ♯ in front marks a chord from outside the key. How Roman numerals work

Progressions

Progressions with C♯m7♭5

Common progressions that use C♯m7♭5, each in a key that spells it C♯m7♭5. The outlined chord is C♯m7♭5.

  • Minor ii–V–i in B minor

    iiø7 – V7 – i7

    1. C♯m7♭5
    2. F♯7
    3. Bm7

    Half-diminished ii, dominant V7 and back to the minor tonic.

    Heard in Blue Bossa, Autumn Leaves

Slash chords

C♯m7♭5 over another bass note

A keeps C♯m7♭5 on top and puts another note in the bass: the letter after the slash is the lowest note you play.

  • C♯m7♭5/E

    C♯m7♭5 with its ♭3rd, E, in the bass: the first inversion.

  • C♯m7♭5/G

    C♯m7♭5 with its ♭5th, G, in the bass: the second inversion.

  • C♯m7♭5/B

    C♯m7♭5 with its ♭7th, B, in the bass: the third inversion.

Questions

C♯m7♭5, in short

What notes are in the C♯m7♭5 chord?
C♯m7♭5 (C♯ 7th) has four notes: C♯, E, G and B, the , ♭3, ♭5 and ♭7.
How do you play C♯m7♭5 on guitar?
C♯m7♭5 has no common . Play it as the A shape at 4 or the E shape at fret 9.
What key is C♯m7♭5 in?
C♯m7♭5 belongs to two keys: D major (viiø7) and B minor (iiø7).
Is C♯m7♭5 the same as D♭m7♭5?
Yes: same frets, same sound, different name. C♯m7♭5 is the spelling in D major and B minor. No key on the circle spells it D♭m7♭5, so you will rarely see that name.
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