In music theory, the dominant seventh flat five chord is a seventh chord composed of a root note, together with a major third, a diminished fifth, and a minor seventh above the root (1, ♮3, ♭5 and ♭7). This chord is enharmonically equivalent to its own second inversion. That is, it has the same notes as the dominant seventh flat five chord a tritone away (although they may be spelled differently). Because of this property, it readily functions as a pivot chord. It is also frequently encountered in tritone substitutions. In this sense, there are only six "unique" dominant seventh flat five chords.
