This dissertation is one of the first book-length contributions on féerie, the French fairy play, and the very first from a music historian. It examines Parisian féerie between the 1864 deregulation of theatres (the chronological endpoint of Roxane Martin’s monograph on the genre) and the turn of the century, relying on an extensive body of hitherto largely overlooked sources. It challenges the conventional wisdom according to which féerie faded into irrelevance during this period by arguing that a lower number of new plays did not mean a reduced presence of féerie on the Parisian stage, as well as by incorporating composerly féerie and scientific féerie into an integrated history of féerie. In fact, composerly féerie (inaugurated by Victorien Sardou and Jacques Offenbach’s Le roi Carotte, 1872) and scientific féerie (inaugurated by Adolphe d’Ennery and Jules Verne’s Le tour du monde en 80 jours, 1874) have long been chiefly associated with operetta and melodrama, respectively. Several concepts are introduced as interpretive tools for late nineteenth-century Parisian theatre: that of “theatre with music,” including all genres where music has an essential role in the dramaturgy, from vaudeville to grand opéra; operettization, the application of operetta-style music to genres beyond operetta; féerization, the spread of féerie dramaturgy beyond traditional féerie; and the “total work of art of the present,” that is, a plurimedial work without centralized authorship, autonomy, or textual stability.