Well, last night was opening night of Can't Live With 'Em, this summer's Boogaloo play, in which I play Benny, a blind roofer.
The opening went more smoothly than we could have imagined, although another actor, who shall remain nameless to protect his dignity, forgot to say his most crucial line, which was critical to establish the storyline for all the scenes that followed. Despite repeated hints, he left the stage, line still unsaid, leaving five actors up there, hanging. Nevertheless, we managed to cover the flub and continue on.
Actually, this is only the third worst thing that can happen onstage (other than forgetting your own lines). Both of the things that are worse than this have happened to me in the past:
> Failed entrance: in Arsenic and Old Lace I played Jonathan Brewster, who is supposed to accost his brother Mortimer when Mortimer bursts onto the set. Except Mortimer didn't do that. Apparently he took a break, and I was left onstage performing an impromptu soliloquy for the benefit of the audience until he could be tracked down and shoved onto the stage.
> Prop/Set failure: in Guys and Dolls I was Nathan Detroit, who ran a floating crap game. This time, the game was set in the sewer*, which meant that actors entering the set did so from a ladder from above. That works pretty well, IF the ladder doesn't collapse, bringing down the set with it. Guess what happened?
This wasn't anywhere near as drastic, and I don't think the audience even noticed.
Check out the song, "In My Memory", which is inspired by the play.
* queue innumerable jokes about floating crap in the sewer.