The thirteenth-century Old French Le Bel Inconnu and its fifteenth-century Middle English analog Lybeaus Desconus demonstrate a startling transformation that may reflect thinking about performance. Le Bel Inconnu expresses ambiguity about the moral valence of both music performance and enchantment, while Lybeaus Desconus intensifies the association of music with magic and expresses disapprobation of practitioners of both. Approaching these romances as performance texts and considering their performativity can illuminate self-referential comments on music and magic and explain motivation for revision of the story.