|Modes||I, II, III, IV, V, VI, VII|
|C, D, E♭, F, G♭, A♭, B♭|
|Number of pitch classes||7|
The half diminished scale or Sisyphean Scale is a seven-note musical scale. It is more commonly known as the Locrian ♮2 scale, a name that avoids confusion with the diminished scale and the half-diminished seventh chord (minor seventh, diminished fifth). It is the sixth mode of the ascending form of the melodic minor scale (or jazz scale).
In the key of B♭, the half-diminished scale built on C is associated with Cm7♭5, which functions as a iiø7 chord in minor (see chord-scale system).