Someone with a future interest in Disney stock is trying to steal the song "Der Zauberlehrling" aka "The Sorcerer's Apprentice"

[Plug Drugs]

In fact I could state that as my own principle: if a section of a wave front changes trajectory from an interaction such that it reverts across a previously present maxima in that wave front, then some quantum number (charge, spin, orbital, flavour, color, etc.) must change.