The Wiener Staatsoper has conceived of its stage curtain as an exhibition space for a museum-in-progress.
Every year since 1998 its safety curtain, which measures 176 meters square, has been used as an exhibition space for a large-format artwork by a contemporary artist. The series has represented a symbolic interface between performance and visual arts, and creates a link between historical questions and contemporary ways to address them.
This according to Curtain/Vorhang by Kaspar Mühlemann Hartl (Wien: Verlag für moderne Kunst, 2017). All of the curtains in the series may be viewed here.
Above, Graduation by John Baldessari, the curtain for the 2017–2018 season. Below, a brief video provides the curtain’s context.
The newly discovered scenic collection of the Stadsschouwburg in Kortrijk, Belgium, comprises 13 backcloths, 21 borders, and over 298 framed units, plus authentic stage furniture, practicables, and sound effects.
This forgotten treasury houses a near-complete set of generic stock sets next to genuine production materials for Aida, La bohème, Carmen, Faust, and other blockbusters from the operatic repertoire. The décors were designed and executed by Albert Dubosq (1863–1940), an acknowledged master of the Parisian school of scenic painting,
Despite the groundbreaking research done at a few historical theaters, the study of operatic iconography still tends to focus on visual renderings—designs, artists’ impressions, and photographs—rather than on primary, scenic artifacts thereof, such as flats and drops. The discovery of these valuable holdings allows new examples of authentic scenery to be subjected to scholarly scrutiny.
This according to “Jumbo-sized artifacts of operatic practice: The opportunities and challenges of historical stage sets” by Bruno Forment (Music in art XXXVIII/1–2  pp. 115–125. Above, Dubosq’s Forêt asiatique for Lakmé; below, his Extérieur égyptien for Aida (both from 1921).