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 glissando upward with the right hand. The "Alborada del gracioso" from Maurice Ravel's "Miroirs" contains glissandi in thirds and fourths in one hand. Octave glissando An octave glissando is a glissando played on the piano by maintaining a constant distance of an octave between the thumb and finger used to execute it, and shifting the whole hand in the direction of the glissando. Due to the positions of the thumbs on the player's hands, octave glissandos are almost always executed upwards with the left hand and downwards with the right. However, exceptions include Balakirev's "Islamey", where players are instructed to execute