In the age of the great melic poets the lyre had no more than seven strings: but the octave was completed in the earliest times of which we have accurate information. The scale which is assumed as matter of common knowledge in the Aristotelian Problems and the Harmonics of Aristoxenus consists of eight notes, named as follows from their place on the lyre:

NÊtÊ (neatÊ or nÊtÊ, lit. 'lowest,' our 'highest').
ParanÊtÊ (paranÊtÊ, 'next to NÊtÊ').
TritÊ (tritÊ, i.e. 'third' string).
ParamesÊ (paramesÊ or paramesos, 'next to MesÊ').
MesÊ (mesÊ, 'middle string').
Lichanos (lichanos, i.e. 'forefinger' string).
ParhypatÊ (parypatÊ).
HypatÊ (hypatÊ, lit. 'uppermost,' our 'lowest').

It will be seen that the conventional sense of high and low in the words hypatÊ and neatÊ was the reverse of the modern usage.

The musical scale formed by these eight notes consists of two tetrachords or scales of four notes, and a major tone. The lower of the tetrachords consists of the notes from HypatÊ to MesÊ, the higher of those from ParamesÊ to NÊtÊ: the interval between MesÊ and ParamesÊ being the so-called Disjunctive Tone (tonos diazeuktikos). Within each tetrachord the intervals depend upon the Genus (genos). Thus the four notes just mentioned—HypatÊ, MesÊ, ParamesÊ, NÊtÊ—are the same for every genus, and accordingly are called the 'standing' or 'immoveable' notes (phthongoi hestÔtes, akinÊtoi), while the others vary with the genus, and are therefore 'moveable' (pheromenoi).

In the ordinary Diatonic genus the intervals of the tetrachords are, in the ascending order, semitone + tone + tone: i.e. ParhypatÊ is a semitone above HypatÊ, and Lichanos a tone above ParhypatÊ. In the Enharmonic genus the intervals are two successive quarter-tones (diesis) followed by a ditone or major Third: consequently ParhypatÊ is only a quarter of a tone above HypatÊ, and Lichanos again a quarter of a tone above ParhypatÊ. The group of three notes separated in this way by small intervals (viz. two successive quarter-tones) is called a pyknon. If we use an asterisk to denote that a note is raised a quarter of a tone, these two scales may be represented in modern notation as follows:

Pynknon

p???? = pyknon

In the Chromatic genus and its varieties the division is of an intermediate kind. The interval between Lichanos and MesÊ is more than one tone, but less than two: and the two other intervals, as in the enharmonic, are equal.

The most characteristic feature of this scale, in contrast to those of the modern Major and Minor, is the place of the small intervals (semitone or pyknon), which are always the lowest intervals of a tetrachord. It is hardly necessary to quote passages from Aristotle and Aristoxenus to show that this is the succession of intervals assumed by them. The question is asked in the Aristotelian Problems (xix. 4), why ParhypatÊ is difficult to sing, while HypatÊ is easy, although there is only a diesis between them (kaitoi diesis hekateras). Again (Probl. xix. 47), speaking of the old heptachord scale, the writer says that the ParamesÊ was left out, and consequently the MesÊ became the lowest note of the upper pyknon, i.e. the group of 'close' notes consisting of MesÊ, TritÊ, and ParanÊtÊ. Similarly Aristoxenus (Harm. p. 23) observes that the 'space' of the Lichanos, i.e. the limit within which it varies in the different genera, is a tone while the space of the ParhypatÊ is only a diesis, for it is never nearer HypatÊ than a diesis or further off than a semitone.