He brings up a nifty little 14th century motet entitled Musicalis Sciencia/Sciencie Laudabili, a sort of satirical piece which takes the form of a dialogue between Music and Rhetoric, who enumerate various stylistic faults musicians and composers are prone to, even as the motet commits each one.
Thus Taruskin:
"Such a satire requires an attitude of ironic detachment, a consciousness of art as artifice, and a wish to make that artifice the principle focus of attention. These are traits we normally (and perhaps self-importantly ) ascribe to the 'modern' temperament, not the 'medieval' one. Only we (we tend to think), with our modern notions of psychology and our modern sense of "self," are capable of self-reflection. Only we, in short, can be 'artists' as opposed to 'craftsmen.' Not so."
(270).
Ditto.
Ditto.