Inspector Mare: C’mon, Princess! What’s the worse they gonna do? Throw a tantrum fit until they throw their singing voice out??

Butler: Actually, that’s exactly what they’re going to do----only they’ll also do a lot much worse if they found out that TWO rival music bands were given the headliner!

Deputy Mare: Care to elaborate on how?

Butler: Hmm...I haven’t got the slightest clue! The worst case scenario is that they’ll write an angry celebrity review about all of you, sue you for reneging on their contract, and attend talk shows to discuss about how you messed on one of the biggest music festivals in all of Equestria.

Second worst scenario is that they spread libel about your character online on social media. Either way, nopony will want to work with you, or trust you with anything after that fiasco....