Heptatonic scale are considered subsets of a twelve-pitch scale roughly analogous to the Western chromatic scale. The first and fifth melakarta tones, corresponding to the first and eighth chromatic tones, are invariable in inflection, and the fourth melakarta tone, corresponding to the sixth or seventh chromatic tone, is allowed one of two inflections only, a natural ("shuddah") position and a raised ("tivra") position. The second and third melakarta tones can be picked from the 4 chromatic tones (second through fifth), and similarly for the sixth and seventh. Thus the number of possible forms is equal to twice the square of the number
Bebop scale by modern practitioners of the bebop genre). The bebop dominant scale is derived from the Mixolydian mode and has a chromatic passing tone between the 7th and the root. \override Score.TimeSignature #'stencil = ##f \relative c' { </score> It has all the notes in both the major scale and the Mixolydian scale of the same root. This scale is often used over dominant seventh chords and all extended dominant chords, and the II-V chord progressions. According to Michael Miller, "[w]hen someone says they're playing 'the bebop scale,' this is the one they're talking about." The bebop Dorian scale (also known