Igitur intervallo tonorum et hemitoniorum et tetrachordorum in voce divisit natura finitque terminationes eorum mensuris intervallorum quantitate,  modisque certis distantibus constituit qualitates, quibus etiam artifices qui organa fabricant, ex natura constitutis utendo comparant ad concentus convenientes  eorum perfectiones.
Therefore by the intervals of tones, semitones, and tetrachords, nature has divided and defined their limits for the voice, measuring them by the quantity of the intervals; and has fixed their quality in certain distinct modes. Craftsmen who make instruments use these proportions which nature has fixed, and make perfect their instruments with a view to suitable concords.
final_alignments\Vitruvius_Architecture_Book_5.json