This article examines Marie Antoinette’s influence on French musical culture in the final decades of the Old Regime. New research in the archives of the royal household (maison du roi) suggests that the preferences of the Austrian-born queen instigated a wholesale reorientation of courtly fashion, away from the serious opera (tragédie lyrique) long favored by the Bourbon monarchs, and towards the lighter and more cosmopolitan strains of opéra-comique. I investigate both how this evolution in taste occurred and, more critically, what it signified: what did it mean fordialogue opera—a genre more commonly linked to the intellectual ferment of Enlightenment than the stolid conservatism of absolute rule—to be appropriated as an “official” royal art? On the one hand, I argue, this development represented a considerable (and potentially subversive) challenge to the rigid hierarchies of French theaters and theatrical forms. On the other hand, somewhat paradoxically, this blurring of generic boundaries was a direct consequence of the new manner that opéra-comique was exploited in the affirmation of monarchy. Put another way, the disruption of dramatic expectations inherent in opéra-comique’s rise was less a mirror of broader socio-political instability than a necessity of the genre’s emerging role within courtly ceremony.