In music theory, a diminished major seventh chord is a seventh chord composed of a diminished triad and a major seventh.[1] Thus, it is composed of a root note, together with a minor third, a diminished fifth, and a major seventh above the root: (1, ♭3, ♭5, 7). For example, the diminished major seventh chord built on C, commonly written as CoM7, has pitches C–E♭–G♭–B:
Diminished major seventh chords are very dissonant, containing the dissonant intervals of the tritone and the major seventh. They are frequently encountered, especially in jazz, as a diminished seventh chord with an appoggiatura[citation needed], especially when the melody has the leading note of the given chord: the ability to resolve this dissonance smoothly to a diatonic triad with the same root allows it to be used as a temporary tension before tonic resolution.
The chord can be represented by the integer notation {0, 3, 6, 11}.
Diminished major seventh chord table
Chord
|
Root
|
Minor third
|
Diminished fifth
|
Major seventh
|
CoM7
|
C
|
E♭
|
G♭
|
B
|
C♯oM7
|
C♯
|
E
|
G
|
B♯ (C)
|
D♭oM7
|
D♭
|
F♭ (E)
|
A (G)
|
C
|
DoM7
|
D
|
F
|
A♭
|
C♯
|
D♯oM7
|
D♯
|
F♯
|
A
|
C (D)
|
E♭oM7
|
E♭
|
G♭
|
B (A)
|
D
|
EoM7
|
E
|
G
|
B♭
|
D♯
|
FoM7
|
F
|
A♭
|
C♭ (B)
|
E
|
F♯oM7
|
F♯
|
A
|
C
|
E♯ (F)
|
G♭oM7
|
G♭
|
B (A)
|
D (C)
|
F
|
GoM7
|
G
|
B♭
|
D♭
|
F♯
|
G♯oM7
|
G♯
|
B
|
D
|
F (G)
|
A♭oM7
|
A♭
|
C♭ (B)
|
E (D)
|
G
|
AoM7
|
A
|
C
|
E♭
|
G♯
|
A♯oM7
|
A♯
|
C♯
|
E
|
G (A)
|
B♭oM7
|
B♭
|
D♭
|
F♭ (E)
|
A
|
BoM7
|
B
|
D
|
F
|
A♯
|
References