public void buildCity() {
        Player p = playerList.getCurrentPlayer();

        if(selected.owner == p && selected.getTile().getCity() == null)
        {
            music.toCity();
            thread.interrupt();//playing battle button
          
            City city = new SmallCity();

            p.addCity(city, selected.getTile());
            p.removeUnit((Unit)selected);
            selected = city;
        }

    }