To understand the emergence of Homeric poetry as an actual written text, it is essential to trace the history of Homeric performance, from the very beginnings of literacy to the critical era of textual canonisations in the Hellenistic and Roman periods. Professor Nagy applies the comparative evidence of oral poetic traditions, including those that survived in literate societies, such as the Provençal troubadour tradition. It appears that a song cannot be fixed as a final written text so long as the oral poetic tradition in which it was created stays alive. So also with Homeric poetry, it is argued that no single definitive text could evolve until the oral traditions in which the epic was grounded became obsolete. In the time of Aristarchus, the gradual movement from relatively fluid to more rigid stages of Homeric transmission reached a near-final point of textualisation.