What catches our attention is the fact that three other copies can be found in the codex where it has been conserved.
In this codex, he introduced the technique of accurately heighting the neumes to show precise relative pitch information.
His contribution to the earliest stages of production is further attested by the ruling system used throughout the main body of the codex.
The illustrations of the edition of the codex are poor and in black and white.
In fact, all of these codices were in the possession of diviners or tonalpouhque.
The likely reason for keeping the two books in separate codices is implied in the very organization of the project.
The author comprehensively studies and presents a relatively neglected late fifteenth-century codex of sacred song.
The other three codices contain hieroglyphic texts in combination with pictorial scenes that form the basis of instruments known as almanacs and tables.
