Dominant seventh flat five chord

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 from root (1, ♮3, ♭5 and ♭7). For example, the dominant seventh flat five built upon C (C7^♭5) would be C-E-G♭-B♭. It can be represented by the integer notation {0, 4, 6, 10}. In diatonic harmony, the dominant seventh flat five chord does not naturally occur on any scale degree (as does, for example, the dominant seventh on the fifth scale degree: C⁷ in F major).

Jazz musicians typically consider the dominant seventh flat five chord to be associated with or built from the seventh mode of the major scale, the Locrian mode. See: chord-scale system and dominant (music).

The dominant seventh flat five may be considered an altered chord, created by diminishing the fifth of a dominant seventh chord, and may use the whole-tone scale^[1], as may the augmented minor seventh chord, or the Lydian ♭7 mode^[2].

Similarly, a minor seventh flat five chord (m7^♭5, also known as a half-diminished seventh chord) is constructed by diminishing the fifth of a minor seventh chord^[3]:

1 ♭3 ♭5 ♭7

C E♭ G♭ B♭.

The minor seventh flat five chord occurs in the diminished scale^[4] on multiple scale degrees as well as on the seventh degree of the major scale (e.g., B-D-F-A in C major).

Dominant seventh flat five chord table

See also

• Altered scale
• French sixth

Sources