Does the audience shape art or does art shape the audience?

I once went to see the Blue Man Group in New York City and was amazed by the show and its unique performance. I began to wonder as I sat there if the show would be the same if the audience was not as willing to become involved in the show. As John Cage writes in his essay, “Diary: Audience 1966", the audience is as much a part of art as the artist himself. This is apparent even today with the changing role of technology and websites providing creative outlets such as Youtube and blogs. 

In these realms, anyone can edit and provide their own art.  By allowing users to upload their own videos, YouTube is letting the audience become the author.  Furthermore, a person viewing the video may be inspired to make their own version or spoof of it.  This further fosters the development of art in the multimedia platform, blurring the line of whether or not art is shaping the audience or the audience is shaping art.  

Another example of the audience shaping art can be seen through a simple Facebook application.  Known as "wall graffiti", this application allows a friend to take a blank virtual space and draw their own "graffiti".  In this sense, the audience is given the paintbrush and control of the art.  Previously, a pre-determined work of art may have been the only option to post on the friend's wall.  However, demands from the audience have helped to develop such an application where the audience creates art.

Overall, it seems that the audience has begun to take an active role in shaping art.