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 [Greek: 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 ([Greek: 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 [Greek: 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. § 17. _Earlier Heptachord Scales._ Regarding the earlier seven-stringed scales which preceded this octave our information is scanty and somewhat obscure. The chief notice on the subject is the following passage of the Aristotelian _Problems_: _Probl._ xix. 47 [Greek: dia ti hoi archaioi heptachordous poiountes tas harmonias tên hypatên all' ou tên nêtên katelipon: hê ou tên] [Greek: hypatên] (leg. [Greek: nêtên]), [Greek: alla tên nyn paramesên kaloumenên aphêroun kai to toniaion diastêma; echrônto de tê eschatê mesê tou epi to oxy pyknou; did kai mesên autên prosêloreusan [hê] oti ên tou men anô tetrachordon teleutê, tou de katô archê, kai meson eiche logon tonô tôn akrôn?] 'Why did the ancient seven-stringed scales include Hypatê but not Nêtê? Or should we say that the note omitted was not Nêtê, but the present Paramesê and the interval of a tone (_i.e._ the disjunctive tone)? The Mesê, then, was the lowest note of the upper [Greek: pyknon]: whence the name [Greek: mesê], because it was the end of the upper tetrachord and beginning of the lower one, and was in pitch the middle between the extremes.' This clearly implies two conjunct tetrachords-- [Music: _e f g a a# c d_ \---- /\----- /]