Walter Benjamin's 1936 essay "The Work of Art in the Age of Mechanical Reproduction" discusses the impact of mass reproduction on the physical arts. text 
Benjamin seems to be discussing for the most part physical artworks like paintings.
The context for his reflection on what paintings had insisted upon (being themselves only in a particular time and place, available only to those who could be there with them) was the emergence and rapid commercial rise of the arts of mechanical reproduction and distribution: photography, recorded music and film.
Sensitivity to political debate about the democratisation of cultural access through mass distribution is key to Benjamin's essay. Benjamin's reflection on the degredation of authenticity when "the cathedral leaves its locale" through the operations of a postcard relates to debates in the US about the impact of film in particular as a highly transportable mass medium whose trade lobbyists were trying to position as a form of art.
The film industry were doing this in order to protect their new industry against the considerable technical cost of post-production censorship, following the conversion of the Hays Code into a binding legal agreement in 1934. At the same time the rapid transition to sound cinema after 1927 was making it very difficult for the musicians whose livelihoods had been boosted by being silent cinema's live orchestral accompanists.
With the performing arts, one has a circumstance where the "authentic" artwork created by the playwright or composer is not the work of art itself but a set of instructions on how to create it (Artwork as Recipe), at least until the creation of automated instruments and sound recording.
Contrast this with the work of Edgard Varèse or Morton Subotnick, who created electronic music. Here the recorded output is the artwork. There is a "score" for Poème Electronique but it's not something that someone else could use to recreate the work. See Varèse Score
See Stravinsky's Player Piano for additional journal history and related ideas. Jason Green (I think??) wrote initial text.