I recently set up my equipment at a new facility and in walked another performer (Elvis act) with his Karaoke stuff. The AD double booked and since it was was my first time and he was a regular, they sent me packing.
As I was carting my stuff away, Elvis' on/off Karaoke button got stuck and he couldn't perform, so I set up all my gear again and played.
The next day I was rebooked, as it went extremely well.
Moral of the story - Elvis left the building