C sharp Dominant seventh flat fifth

The 7♭5 dominant emphasizes tritone character and introduces a leaner, unstable fifth. It sounds tighter and more angular than a plain dominant seventh, making it effective for tension-forward harmony.

Construction

Formula: 1-3-♭5-♭7 (optionally with 9/13 context). In C: C-E-G♭-B♭. 3 and ♭7 keep dominant function while ♭5 sharpens dissonance.

Usage

Common in jazz turnarounds, altered dominant preparation, and chromatic passing dominants.

Play

Voice 3 and ♭7 clearly, keep ♭5 present but balanced, and resolve inward or outward by semitone for a convincing cadence.