What is art?

In the Sinnreich reading, I found myself asking how do you define art? while people weighed in on their opinion of configurable music as art. Their answers all depended on individual interpretations of what art is. I really liked Marc Geiger's quote, "if the audience thinks it's art, then it's art." I don't believe there's is a tangible definition of art, and whether a piece of work exists as art depends entirely upon audience perception. A really good example is Andy Warhol's work. Most people look at a campbell's soup can and see it as a commodity, but by taking the image, and passing it off as art, Warhol's reproduction is considered by many to be among the most important artwork of the  20th century. I remember reading about Warhol and asking myself, "why his work was so highly regarded." I googled his name, looking for an explaination, and there was no consistent answer.