Also written C♯dimMaj7, C♯dimM7 or C♯°M7
C♯ diminished major 7th contains C♯, E, G, and B♯. The open position uses two open strings and a middle-finger stretch to the 3rd fret.
The same three notes, with a different one in the bass.
C♯ diminished major 7th is built from the formula 1, ♭3, ♭5, 7. The major 7th interval between C♯ and B♯ gives it a sharp leading tone. Compare it to C♯ minor 7th flat 5th, which lowers the 7th to B.
C♯ diminished major 7th works as a passing chord in C♯ minor or C♯ major contexts. Use it to lead into C♯ minor or C♯ major. Its tense sound suits jazz and gypsy minor lines.
The open position keeps the bass on C♯, giving a clear root. The C♯dimM7/E inversion moves the bass to E for a softer sound, and the C♯dimM7/G inversion puts the diminished 5th in the bass for a darker edge.
C♯ diminished major 7th is played in open position as 0 1 0 3: index finger on the C string at fret 1 and middle finger on the A string at fret 3. The G and E strings ring open.
Tip — The middle finger must reach the 3rd fret on the A string without touching the open E string.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | open | — | G (♭5) |
| 3 (C) | 1 | 1 | C♯ (1) |
| 2 (E) | open | — | E (♭3) |
| 1 (A) | 3 | 2 | B♯ (7) |
C♯ diminished major 7th is played at the 3rd fret as 5 4 3 4: pinky finger on the G string at fret 5, middle finger on the C string at fret 4, index finger on the E string at fret 3 and ring finger on the A string at fret 4.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 5 | 4 | B♯ (7) |
| 3 (C) | 4 | 2 | E (♭3) |
| 2 (E) | 3 | 1 | G (♭5) |
| 1 (A) | 4 | 3 | C♯ (1) |
C♯ diminished major 7th is played at the 6th fret as 6 7 8 7: index finger on the G string at fret 6, middle finger on the C string at fret 7, pinky finger on the E string at fret 8 and ring finger on the A string at fret 7.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 6 | 1 | C♯ (1) |
| 3 (C) | 7 | 2 | G (♭5) |
| 2 (E) | 8 | 4 | B♯ (7) |
| 1 (A) | 7 | 3 | E (♭3) |
C♯ diminished major 7th is played in open position as 0 0 0 4: index finger on the A string at fret 4. The G, C and E strings ring open.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | open | — | G (♭5) |
| 3 (C) | open | — | B♯ (7) |
| 2 (E) | open | — | E (♭3) |
| 1 (A) | 4 | 1 | C♯ (1) |
C♯ diminished major 7th is played at the 3rd fret as 6 4 3 3: barre your index finger across fret 3, ring finger on the G string at fret 6 and middle finger on the C string at fret 4.
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 6 | 3 | C♯ (1) |
| 3 (C) | 4 | 2 | E (♭3) |
| 2 (E) | 3 | 1 (barre) | G (♭5) |
| 1 (A) | 3 | 1 (barre) | B♯ (7) |
C♯ diminished major 7th is written C♯°M7 or C♯dimM7, and the ASCII root is C#. It is also spelled D♭ in enharmonic notation for the same sounding root.
C♯ diminished major 7th has a major 7th (B♯), while C♯ minor 7th flat 5th has a minor 7th (B). That one semitone changes the chord's color completely.
C♯ diminished major 7th contains a tritone between C♯ and G and a major 7th between C♯ and B♯. Both intervals create strong dissonance that wants to resolve.