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
Von Luschan's chromatic scale of the skin type of individuals introduced in 1975 by Harvard dermatologist Thomas B. Fitzpatrick to describe sun tanning behavior. The von Luschan scale was used extensively throughout the first half of the 20th century in race studies and anthropometry. However, the results were inconsistent: in many instances, different investigators would give different readings of the same person. The von Luschan scale was largely abandoned by the early 1950s, replaced with methods utilizing reflectance spectrophotometry. The following table shows the 36 categories of the von Luschan scale in relation to the six categories of the Fitzpatrick scale: Von Luschan's chromatic