In the copyist edition penned in the years 1333-4 of the famous "Book of (Musical/Rhythmic) Cycles (or Circles of Beats and Scales/Octave Species) with regards to the Science of Music" ( ﻛﺗﺎب اﻻدوار ﻓﻲ ﻋﻠم اﻟﻣوﺳﯾﻘﻲ transliterated as "Kitāb al-adwār fīʿilm al-mūsīqī") written by Safi al-Din Urmawi and dated to 1233, there exists a well-detailed Oud graphic which is of critical import, and on whose neck can be seen a fretboard that has eluded disclosure up until today. If one scrutinizes this graphic (that is presented to us in the form of a more elaborate depiction of the already-existing and perspective-wise trapezoidally-oriented Oud neck drawing in the original Book of Cycles from 1233), it would seem that it is possible to resolve all at once, in the tractates of Urmawi, and through a novel approach, the outwardly conflicting i) 17-tone Pythagorean system, ii) method of attaining individual genera like Isfahan and Rahawi in line with Hellenistic music theory via their much more different division, iii) Zalzalian ratios pertaining to the fretting of the Oud as transmitted from Farabi, and iv) insinuation of even more dissimilar octave-spanning scales arising from Yarman's insertion of the said partitioned individual genera to the related Pythagorean scales. The novel approach in question involves the calculation-wise katapyknotic --- viz., visually arithmetical --- equipartitioning of the pure fourth into 7 portions as per the aforementioned Oud drawings, and then the slight sliding down of the 3rd fret towards the bridge so as to achieve perfect octave equivalences with the open bass courses Bamm, Mathlath and Mathna. As such, the principal guidelines of millennial maqam accumulations get resurrected in what can be said to constitute, intonation-wise, an authentic Iraqi-Iranian-Arabian setting. The first co-author had already laid out his revolutionary finding in his 40-minutes-long YouTube channel upload (https://youtu.be/Mdaok224BvE) titled "Demystifying Urmawi" on 2 September 2023 in extensive detail, and furthermore delivered several compositions to demonstrate its validity. Under the framework of such a discovery, the correct understanding of the musical scales of Urmawi and their contemporaneous impact will be elaborated, which leads to the full restoration and revival of authentic intonational meaning to what this legendary figure was actually trying to explain. (To hear the end results, cf. the YouTube playlist of the decoded
Yarman et al. (Mon,) studied this question.