I did the performance and got away with it again. Fate did its best to scare the crap out of me. They put me on the list after this bloke I know who hadn't arrived yet, and then they told me that if he didn't arrive then I'd be after the one before, so I had to learn their name quick, and I was sitting there not knowing whether he'd arrive or not.
Then he did arrive so I thought I knew my job, just wait till he started playing and then go backstage to prepare to walk onstage in a timely manner. But when the act before him was nearly done I thought I'd better go backstage just to make sure everything was running like I thought. I looked at the list and saw that the bloke's name had been crossed off and somebody else's name written in. He was called Noshow.
So I asked what Noshow looked like, thinking it was an odd name, and got told that it said "no show" and I was on next. The bloke had decided to play later on so he'd have more time to set up. I only had time to tune 3 strings before I had to start, and had to trust to luck that the other 3 were still more or less in tune.
Anyway, as it turned out, the guitar was pretty much in tune and for some reason I was the least nervous I'd ever been there, in spite of all the chopping and changing, and I did quite well. They liked my performance. It makes me happy when something that could have gone very badly goes very well.