As I understand it, the original music box tune was a stock composition by Robert Farnon (it turns up in other programs from the era, including "The Prisoner: Dance of the Dead"). Dan Curtis eventually got Cobert to adapt the tune into "Josette's Music Box," but I'm not sure if that was because he didn't want to pay royalities to Farnon or because he simply wanted something more original for DS.
ProfStokes