[2] Later sections draw heavily on the music theory of Boethius and Cassiodorus, two early medieval authors whose works on music were widely read and circulated hundreds of years after their death.
The treatise makes use of the monochord to explain interval relations.
The treatise also discusses singing technique, ornamentation of plainchant, and polyphony in the style of organum.
This notation has a number of figures which are rotated ninety degrees to represent different pitches.
A critical edition of the treatises was published in 1981, and an English translation by Raymond Erickson in 1995.