The music box will play a piece of music when you first investigate. This music is a sample. Every time you change the switch, a new piece of music will play. You need to use these switches to combine The music it plays. But the standard trick in the game is that there are two music boxes in the half circle of the hall on the first floor, which will play two different kinds of music correspondingly. The order of switching is marked on the box. Game veterans all know that it is either "up, down, up, down, up" or "down, up, down, down, up and down", with the first one being the most likely (I remember encountering the second situation).