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
Short octave composer Peter Philips wrote a pavane in which the left hand plays many parallel tenths. This is a considerable stretch for many players, and become even harder when (as in Philips's pavane), there sometimes other notes included in the chord. Of this piece harpsichord scholar Edward Kottick writes, "The sensuality of effortlessly achieving tenths is so strong, so delightful, that one cannot really claim to know the piece unless it has been played on a short-octave keyboard." A later composer who wrote music conveniently playable only on a broken-octave instrument was Joseph Haydn, whose early work for keyboard was intended