Hi there! Laurel here.
As I read your comments, I started to think harder about my own onstage disasters, and have been surprised to realize that nothing I have experienced constitutes a real disaster. Perhaps this is because so many of the things that can go wrong onstage have gone wrong on, and more than once, and yet I survived, with bruised feelings and ruffled feathers, but also with such great stories to tell that the mishaps look like little presents when seen in hindsight.
I have driven from upstate New York to a gig in Indianapolis, only realizing that my clothes were still hanging by the front door of my house when I was but 50 miles from my destination. No open shops - the gig was on a Sunday - so I borrowed clothes from one of the very kind waitresses at the venue, and spent the rest of the evening alternately singing songs and explaining why I wasn't bringing the drinks.
I have been in the middle of a ballad when - on separate occasions - the following things happened: pedal assembly fell off the piano (loud sound), steamboat bellowed its horn (very loud sound), sound board patches in a multi-theater venue got switched and I was suddenly and briefly a rock musical (louder still), and (my favorite) as I was singing "Interlude", at the line "a fly-by-night affair" a big ol' horsefly moseyed past my face about an inch from my nose, and I swear it waved at me as it was going by (small sound of choked hysterical laughter followed by about a month of not being able to sing that song at all without laughing to the point of tears).
Once during a Manhattan Transfer performance, Alan Paul took off his tuxedo jacket and tossed it toward me. I caught it with my very long perfectly manicured fingernails... all of which broke at once. I was in a snit for a while, but it was a fine performance gesture on his part.
Somewhere in Australia I was surprised by a fan who jumped up on the stage, lunged at me, and bit my leg. She was in turn surprised by the sound man who grabbed her and removed her from the stage.
All of these (except the fly) felt shattering when they happened...and not one of them has left any residue other than a good story and a certain comfort level with things going awry. The audience's response to anything that goes wrong onstage is determined by how we react. Generally, if we can handle it, they can, too.
The Oxford English Dictionary defines disaster as "a sudden or great misfortune; an event of ruinous or distressing nature, a calamity; complete failure". Its origins are Latin, dis astrum, meaning ill-starred, or an unfavorable aspect of a star.
Which of course is something we never want to be inflicting on the audience.