Although the Middle Ages was a period marked by a passion for summae, it also developed a taste for short forms. In the case of thirteenth-century music, the vernacular motet, with its syllabic style and single stanza, offers a sharp contrast with the prolix forms of the organum, the conductus and the chanson. This article focuses on one of the shortest works in the repertoire, the motet Hé! Monnier! / (preti)osus. This piece is as remarkable for its brevity as for the clash of its two voices: a curious little scene in obscene language staging a miller and a woman is based on a tenor stemming from a response for the feast of Saint Denis. The article clarifies the functions of this short form by contextualising the dramatic motetus sketch within medieval and modern song and literature, then by untangling the mechanism that links this folkloric formula to the Saint Denis chant fragment.