The chains are hanging around of the kingdom as a decoreations.
The are a decoraitioins of the movie The Swan Princess Chistmas and they are put by Derek mother the Queen Uberta, as: A Swan Princess Christmas witch Odette likes it. But this made Rothbart visible. and Derek is witness to see Rothbart, and he put them everywhere at the palace so Rothbart can't harm Odette or anybody.
It plays the love song of Derek and Odette.