  In aesthetics, it is generally necessary to distinguish works of art themselves (types) from their physical incarnations (tokens). (See, for example, Wollheim 1968, Wolterstorff 1980 and Davies 2001.) This is not the case with respect to oil paintings like the Mona Lisa where there is and perhaps can be only one token, but seems to be the case for many other works of art. There can be more than one token of a sculpture made from a mold, more than one elegant building made from a blueprint, more than one copy of a film, and more than one performance of a musical work. Beethoven wrote nine symphonies, but although he conducted the first performance of Symphony No. 9, he never heard the Ninth, whereas the rest of us have all heard it, that is, we have all heard tokens of it.