The Cambridge History of Fifteenth-Century Music
Fifteenth-century Italy witnessed a distinctive chapter in the ancient and global history of oral poetry. Aspects of Renaissance Italian poetic performance are clearly linked with oral practices of all times and places: the conception of poetry as a multivalent and nearly universal form of human discourse, a tendency for poetic voice to culminate in song (often instrumentally accompanied), and the inseparability of oral poetry from the agonistic environment of performance. The interrelated operations of memory and improvisation, too, played essential roles: music was never notated and always improvised, while the poetry was sometimes improvised but may have been conditioned by writing. The capacity of a well-trained memory to engage in both recall and combinatorial invention meant that while "improvisation" of text or music almost always involved some element of composition in performance, it was rarely ex nihilo, but involved the refashioning (rifacimento) of preexistent materials.
Wilson, Blake. "Canterino and Improvvisatore: Oral Poetry and Performance." In The Cambridge History of Fifteenth-Century Music, edited by Anna Maria Busse Berger and Jesse Rodin, 292-310. Cambridge, UK: Cambridge University Press, 2015.