C♯ diminished major 7th chord on guitar (C♯dimMaj7)

Also called or written C♯dimMaj7, C♯dimM7, C♯°M7, C♯ augmented minor seventh or C♯ minor seventh sharp five

C♯ diminished major 7th is built from C♯, E, G and B♯. The 4th fret shape mutes both E strings, which are chord tones here.

4frC♯GB♯EEADGBE
Positions on the neck1 of 5
Practice C♯ diminished major 7th chord

How it is built

C♯RootEMinor thirdGDiminished fifthB♯Major seventh

Formula 1, ♭3, ♭5, 7

Inversions
  • Root positionC♯–E–G–B♯C♯dimMaj7×-4-5-5-5-×
  • First inversionE–G–B♯–C♯C♯dimMaj7/E0-3-2-0-2-0
  • Second inversionG–B♯–C♯–EC♯dimMaj7/G3-3-2-0-2-0
  • Third inversionB♯–C♯–E–GC♯dimMaj7/B♯×-3-2-0-2-0

How do you play a C♯ diminished major 7th chord on guitar?

C♯ diminished major 7th is played at the 4th fret as × 4 5 5 5 ×: index finger on the A string at fret 4, middle finger on the D string at fret 5, ring finger on the G string at fret 5 and pinky finger on the B string at fret 5. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)41C♯ (1)
4 (D)52G (♭5)
3 (G)53B♯ (7)
2 (B)54E (♭3)
1 (e)muted

AdvancedThe four-fret stretch from index on A4 to pinky on B5 is wide, and both E strings must be muted despite being chord tones.

9th fret

C♯ diminished major 7th is played at the 9th fret as 9 10 10 9 × ×: index finger on the low E string at fret 9, ring finger on the A string at fret 10, pinky finger on the D string at fret 10 and middle finger on the G string at fret 9. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)91C♯ (1)
5 (A)103G (♭5)
4 (D)104B♯ (7)
3 (G)92E (♭3)
2 (B)muted
1 (e)muted

11th fret

C♯ diminished major 7th is played at the 11th fret as × × 11 12 13 12: index finger on the D string at fret 11, middle finger on the G string at fret 12, pinky finger on the B string at fret 13 and ring finger on the high e string at fret 12. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)111C♯ (1)
3 (G)122G (♭5)
2 (B)134B♯ (7)
1 (e)123E (♭3)

C♯dimM7/E inversion · E on top

C♯ diminished major 7th is played in open position as 0 3 2 0 2 0: ring finger on the A string at fret 3, index finger on the D string at fret 2 and middle finger on the B string at fret 2. The low E, G and high e strings ring open.

Full note and interval breakdown
StringFretFingerNote
6 (E)openE (♭3)
5 (A)33B♯ (7)
4 (D)21E (♭3)
3 (G)openG (♭5)
2 (B)22C♯ (1)
1 (e)openE (♭3)

C♯dimM7/E inversion · G on top

C♯ diminished major 7th is played in open position as 0 3 2 0 2 3: ring finger on the A string at fret 3, index finger on the D string at fret 2, middle finger on the B string at fret 2 and pinky finger on the high e string at fret 3. The low E and G strings ring open.

Full note and interval breakdown
StringFretFingerNote
6 (E)openE (♭3)
5 (A)33B♯ (7)
4 (D)21E (♭3)
3 (G)openG (♭5)
2 (B)22C♯ (1)
1 (e)34G (♭5)

Why it sounds like that

C♯ diminished major 7th uses the formula 1, ♭3, ♭5, 7. The diminished 5th between C♯ and G creates a tritone, and the major 7th B♯ is the leading tone. Compare it to C♯ minor 7th flat 5th, which lowers the 7th to B.

What goes wrong with C♯ diminished major 7th?

  • Letting the low E string ring open and doubling the bass.
  • Flattening the ring finger onto the B string and muting the 5th.

When to use it

C♯ diminished major 7th works as a passing chord in C♯ minor, often moving to C♯ minor or C♯ major 7th. The leading tone B♯ pulls to C♯, so use it before a C♯ major cadence. It suits gypsy jazz and dramatic film cues.

Changing to and from C♯ diminished major 7th

  • Sliding the shape down one fret to the 3rd fret gives C diminished major 7th.

Which voicing to use

The 4th fret shape keeps the bass on C♯ and is the default. The 9th fret position repeats the voicing an octave higher, while the 11th fret adds a brighter register for solos.

Other C♯ chords

Common questions

How is C♯ diminished major 7th written?

C♯ diminished major 7th is written C♯°M7 or C♯dimM7. The ASCII root spelling is C#. It is also spelled D♭ in enharmonic notation for the same sounding root.

What is the difference between C♯ diminished major 7th and C♯ minor 7th flat 5th?

C♯ diminished major 7th has a major 7th, B♯. C♯ minor 7th flat 5th lowers that note to B, creating a dominant-quality chord.

Why does C♯ diminished major 7th sound so tense?

The diminished 5th between C♯ and G creates a tritone, and the major 7th B♯ rubs against the root. Together they produce a strong leading-tone pull.