A sharp Diminished seventh major seventh

The label diminished seventh with major seventh (sometimes written as a combined symbol like o7M7) suggests a sonority that mixes the symmetric diminished-seventh frame with a major seventh interval above the bass. In practice, charts using this label may intend different spellings depending on the editor: sometimes a polychord effect, sometimes a particular upper-structure voicing, sometimes an enharmonic reinterpretation of a smaller pitch set. Treat it as a specialist symbol and always trust the recording or the part’s voice leading.

Construction

Interpretation varies; commonly discussed as overlapping diminished and major-seventh colors in advanced jazz or film harmony.

Usage

Climax sonorities, experimental textures, and deliberate “impossible” harmonic moments.

Examples

• Modern orchestral and synth pads
• Contemporary jazz voicings that stack unrelated tertian layers
• Film scoring for surreal harmonic shifts

Play

Thin the voicing; assign each pitch a role in voice leading; avoid uncontrolled doubling.

Ear-training cues

Highly chromatic, symmetric diminished color colliding with a bright major-seventh impression at the top.