It is imperative, in a lexicon such as Wikipedia, that all terms in use have their place for the arts.  If art is mostly referring to the "visual arts", then that is its common usage, but that does not represent the whole story. Art as a term has many interpretations, because we have carried that same term through many centuries, and as society has developed new methods of expression, the term art has also evolved.  Since everyone cannot agree on only one usage of a word that has such a long history, it needs its own pages.  I think the article on Art is accomplishing its purpose, and doing it better every day as it is refined here on Wikipedia.