The original question had to be edited. In some ways, Schaffer's work might be able to be seen as representative of Artaud's theories on the theatre of the cruel. Artaud's theories on this condition of the theatre is rooted in the idea that there has to be some purification that the audience experiences with what is seen on stage. Artaud believes that the modern setting is something that theatre does not address. With its emphasis on "old tragedies" and replaying contextual work that does not speak to the modern context, Artaud wanted a theatre of the cruel that would be unrelenting in exposing aspects of human consciousness that the audience could experience as they are watching the characterizations unfold. There had to be a new set of "nonverbal language of sights, sounds, and gestures" that would forge connection.
Schaffer's work could be seen in this light. The "nonverbal language of sights, sounds, and gestures" to which Artaud alludes could be the presence of music and its deconstruction. The manner in which Schaffer breaks down parts of Mozarts's works to enhance characterization and plot is one such way in which a new nonverbal frame of reference is enhanced. The drama speaks to something fundamentally human in the modern setting in ters of the sin of coveting. There is a uniquely modern condition of envy displayed. This notion of coveting what we don't have is something that Salieri displays in such an open and raw way. It helps to illuminate Artaud's theory of the cruel in that the audience recognizes its own mediocrity in their lives as Salieri understands his own. When he speaks of being the embodiment of all failures, the audience sees their patron saint on stage. It is a moment of purification and one in which Artaud's theories can be seen as being represented.
While Artaud used his theory to speak to a larger condition being illustrated such as wars or revolution and larger statements of being, I think that one could see Schaffer's work striving to speak to a condition in which individual identity is something larger. It strives to articulate an identification with the audience, transforming them from passive observers to active participants as to what it means to be human. Artaud's theory speaks to this transformation being critical to what theatre is and what it hopes to accomplish.