Aesthetics of Silence (1967)

The exemplary modern artist's choice of silence isn't often carried to this point of final simplification, so that he becomes literally silent. More typically, he continues speaking, but in a manner that his audience can't hear. Most valuable art in our time has been experienced by audiences as a move into silence (or unintelligibility or invisibility or inaudibility); a dismantling of the artist's competence, his responsible sense of vocation — and therefore as an aggression against them.
Modern art's chronic habit of displeasing, provoking, or frustrating its audience can be regarded as a limited, vicarious participation in the ideal of silence which has been elevated as a prime standard of seriousness in the contemporary scene.
But it is also a contradictory form of participation in the ideal of silence. It's contradictory not only because the artist still continues making works of art, but also because the isolation of the work from its audience never lasts. With the passage of time and the intervention of newer, more difficult works, the artist's transgression becomes ingratiating, eventually legitimate. Goethe accused Kleist of having written his plays for an "invisible theatre." But in time the invisible theatre becomes "visible" The ugly and discordant and senseless become "beautiful." The history of art is a sequence of successful transgressions.
Susan Sontag.
The Aesthetics of Silence. 1967.