One fact that an Artist and their Audience agree upon is the identity of the resulting Art work. The classic exposition of this principle is the hoary old story about Marcel Duchamp displaying a toilet at an art exhibit in New York City in 1917 and having it disqualified by the Judges, but of course, everyone agreed that the toilet was Art, just disagreed on whether it was "good" Art, which is another question entirely.
|Andy Warhol Soup Can|
The agreement between Artist and Audience over the identity of the art work is a given, but nothing about the identity of the Artist is fixed in the same way. The solid feeling critics have at being able to point at an Album, Painting, Sculpture, Building etc. and saying "that is the Art Work." Is only matched by the vaporous fumes that the same critics sniff when trying to explain "that is the Artist." One is a concrete, almost physical description, the other is the most ephemeral of all critical judgments.
A good way to illustrate what I'm talking about is the work and identity of Andy Warhol. Warhol was a prolific studio Artist who made drawings, paintings, prints, silk screens, film, music and sculpture Even though Warhol was a prolific Artist in terms of works, he was even more prolific in terms of establishing and expanding his Artistic identity. With Warhol, this is an easy concept to grasp because one of the characteristics of his Artistic identity was as an apostle of fame and celebrity. This concern is also present of much of Warhol's work itself, but it extended off the canvas, so to speak.
The point I'm trying to make here is that an Artist can create many different kinds of works and have a separate identity as an Artist, independent from any one work. Something that often happens in the more popular Artistic fields is that an Artist becomes tied to one specific work, and that work dwarves the independent identity. Think of Fall Out Boy for a contemporary example of that phenomenon.