Add genre to works

[robertmhudson]

Possible model for adding genre to statements about musical works:

<works/nnn> schema:genre <genres/folkSongs>.

<genres/folkMusic> a skos:Concept;
  skos:prefLabel "Folk songs";
  skos:inScheme <genres/>.
  skos:closeMatch dbpedia:Folk_music,  <http://id.loc.gov/authorities/genreForms/gf2014026809>

<genres/> a skos:ConceptScheme;
  rdfs:label "Work genres";
  rdfs:comment "For now is a small thesaurus, and only Works with anonymous composers have schema:genre values".

This example focuses on Folk Songs and Spirituals, for which the creator is an anonymous composer.
Thanks to @VladimirAlexiev for suggesting this improvement.