The texts of thirteenth-century vernacular motets have held centre stage in many recent debates about this polytextual genre: the purported unintelligibility of the words in performance has led to questions about how motets were meant to be understood, especially by third-party listeners, both medieval and modern. The irony is that the purpose of the music has gone unheard in this debate. Using a single motet as point of focus, this article suggests various ways in which the music clarifies rather than obscures the meaning of the text in performance. These range from the use of simple musical devices, such as musical repetition or changes in texture that draw attention to significant moments in the text, to the exploitation of refrain melodies, which I argue carries out an ‘intersonic’ duty that serves as an interpretive companion to the more traditional ‘intertextual’ readings of recent scholarship.