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
Diatonic and chromatic contrast, the remaining bars are highly chromatic, using all the notes available to convey a sense of growing intensity as the music builds towards its expressive climax.] A further example may be found in this extract from Act III of Richard Wagner’s opera "Die Walkure" . The first four bars harmonize a descending chromatic scale with a rich, intoxicating chord progression. In contrast, the remaining three bars are entirely diatonic, using notes only within the scale of E major. The passage is intended to convey the god Wotan putting his daughter Brunnhilde into a deep sleep. <score vorbis="1"> { \relative