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
Pentatonic scale Pentatonic scale A pentatonic scale is a musical scale with five notes per octave, in contrast to the more familiar heptatonic scale that has seven notes per octave (such as the major scale and minor scale). Pentatonic scales were developed independently by many ancient civilizations—an indication that pentatonic scales are based upon a naturally occurring phenomenon. They are still used all over the world, for example (just to name a few) Chinese music and US country music and blues. There are two types of pentatonic scales: those with semitones (hemitonic) and those without (anhemitonic). Pentatonic scales occur in the following