Often neglected in the musicological coverage of revolutionary music and theater, the Thermidorean Reaction phase (1794–1795) of the French Revolution was a period of governmental transition, in which Parisian theaters enjoyed the institutional and generic freedoms of the Le Chapelier Laws of 1791 in addition to relaxed enforcement of censorship. In recent years, Mark Darlow and Julia Doe's work has advanced understandings of operatic genres during the early years of the Revolution, which they characterize as a balance between "rupture and continuity" with artistic conventions of the ancien régime. I extend their methods of analysis to the second half of the revolutionary decade, exploring the impact that Thermidorian theatrical politics and legal (de)regulations had on operatic genre through the lens of Sapho (1794). This tragédie lyrique premiered at the Théatre de Louvois, a venue of ambiguous status within Paris's theatrical hierarchies. Featuring a libretto by Constance de Salm and music by Jean-Paul-Égide Martini, Sapho falls within the period of temporarily suspended theatrical privilege initiated by Le Chapelier and borrows key formal elements from "great" and popular operatic styles. The opera facilitates a discussion of how composers and librettists collaborated to navigate the rapidly shifting political and legal climate of Thermidor. I argue that Sapho's careful blend of generic consistency and innovation arose from its twofold institutional and aesthetic positioning. Institutionally, it premiered within a period of relaxed theatrical regulations at a theater, the Louvois, that avoids clear categorization. Aesthetically, Sapho represents a culmination of generic developments initiated in the 1750s, with innovative musical and formal elements stemming from the authors' attention to dramatic progression and their desire to remain artistically relevant in the wake of the Terror.