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
Tonic sol-fa latter more directly represents the intervals between pitches in any given key signature. In Curwen's system, the notes of the major scale (of any key) are notated with the single letters d, r, m, f, s, l, and t. For notes above the principal octave, an apostrophe follows the letter; notes below the principal octave have a subscript mark. Chromatic alterations are marked by the following vowel, "e" for sharp (pronounced "ee") and "a" for flat (pronounced "aw"). Thus, the ascending and descending chromatic scale is notated: Such chromatic notes appear only as ornaments or as preparation for a modulation;