def song_history
    song_okeys = Render.find(:all, :select => 'DISTINCT(song_okey)', :joins => 'LEFT OUTER JOIN projects ON renders.project_id = projects.id LEFT OUTER JOIN users ON projects.user_id = users.id', :conditions => ['users.id = ?', self.id], :order => 'renders.created_at DESC').map { |o| o.song_okey }
    song_library = commercial? ? API::Song::commercial_library : API::Song::consumer_library
    history = []
    song_okeys.each do |okey|
      # Library consists of an array of arrays
      song_library.each do |i|
        i.each do |j|
          history << j if j.id == okey
        end
      end
    end
    history
  end