Define Art

This week in the reading we discussed the ideas of Morris Weitz and his theory of the non definable art. Weitz argues that art is so open and large that is no actual way to define it. Despite this; however, in his attempt to justify the fact that art is incapable of bing defined, he almost gives it a working definition. First off, art is something that appeals to an aesthetic. We have discussed before that art can only be considered art if it is capable of appealing to the aesthetic values of the viewer or the producer. Art, however, is something that is pertaining to a physical thing. The representation that is being made is a replication of a physical thing. From the point of appealing to aesthetics, art can then be broken down into genre and then medium. The genre represents different types of art for example music and the medium represents a sub category within the genre; i.e. drums or other instruments.
From here is where the "definition" gets kind of fuzzy. It may seem obvious now that there is a somewhat functional definition of art here, however this almost limits what can be referred to as art. Almost anything can be art however, not everything can be functioned past that down to genre or medium. For example, styling hair. Styling your own hair is not considered art but having someone style your hair is. Without the work of it being done and accomplished by someone, it is really just an aesthetic.
Therefore, a question rises. If anything can be considered art but only some things can be functioned down  further, does that mean only true art is able to be a genre or medium of art?