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
Hungarian minor scale indicates a half step, and + indicates an augmented second (the latter of which is enharmonically equivalent to a minor third but is notionally distinct). The scale contains two augmented seconds, one in each tetrachord. It also contains an augmented fourth (which is enharmonically identical to a tritone) between the first and fourth degree. Intriguingly, this scale (and its modes like the double harmonic scale) is the only seven-note subset of the equally tempered chromatic scale that is "perfectly balanced"; this means that when its pitches are represented as points in a circle (whose full circumference represents an octave), their