Genus (music) the other hand, also has twelve pitches to the octave, but the semitones are all of the same size. In contrast, the ancient Greek chromatic scale had seven tones to the octave (assuming alternating conjunct and disjunct tetrachords), and had incomposite minor thirds as well as semitones and whole tones. The (Dorian) scale generated from the chromatic genus is composed of two chromatic tetrachords: whereas in modern music theory, a chromatic scale is: The number and nature of the shades of the chromatic genus vary amongst the Greek theorists. The major division is between the Aristoxenians and the Pythagoreans. Aristoxenus
Octave mandolin distinction is not crisp, and there are cases of each term being used in each country. Jimmy Moon, a Scottish luthier calls his version of the instrument by both names and Paul Shippey, an English luthier, uses the term octave mandolin. Confusion will likely continue as the terms continue to be used interchangeably. Octave mandolin construction is similar to the mandolin: the body may be constructed with a bowl-shaped back according to designs of the 18th-century Vinaccia school, or with a flat (arched) back according to the designs of Gibson Guitar Corporation popularized in the United States in the early