Music, the Market, and the Marvellous examines féerie, the French fairy play, in the last third of the nineteenth century. It is among the first book-length studies on the genre, the first in a language other than French, and the first from a musicological perspective. Sabbatini demonstrates that, contrary to conventional wisdom, féerie was still thriving during the fin de siècle, giving rise to innovations such as composerly féerie and scientific féerie. The plays, the theatre industry, and urban geography are discussed together, as befits a commercial genre where the marvellous was shaped by the market. Recovering this forgotten ^—^ but once hugely influential ^—^ repertoire provides an occasion to rethink generic taxonomies of Parisian theatre and the ontology of nineteenth-century 'popular' theatre.