In any city, in any country, go to any mental institution or halfway house you can get yourself to. When you reach the front desk, ask to visit someone who calls herself "The Holder of Song.” You will then be guided to a single door leading to a long, winding staircase. It will spiral higher than the building stands; at the top is a door that opens into a hallway. The music box is Object 6 of 538. When its song plays again, they will all come together.