The 1st (unaccompanied) one was embarrassing. I had never sung in front of people before and was very nervous about it. To settle in, I played a lengthy instrumental introduction (3 minutes or thereabout) to Pretty Polly. Finally I sang the opening line and... stopped dead. I had forgotten the 2nd line and had to stop.
The last one (Saturday 24th July) could have been worse if I had my way. It was a wedding. This little kid kept invading the stage. I kept shooing him away as we were setting up (Im the nasty in the band). Later someone let him blather into one of the sax mics. It was the only one he could reach. By the time we were up and playing there was no stopping the little perisher. He pulled himself up, grabbed a tambourine, trod on my GT5 unit changing the guitar sound from clean accompaniment to balls out lead. Someone fetched him off, but within seconds he was back, robbed the drummer of one of his sticks, which buggered up the drums. He did this countless times. He was like greased lightning getting up on that stage. He made me too nervous to play well, I was watching him all the time. I could cheerfully have strangled the little sod. Turned out he was the brides son. Just as well I didnt then.
Ive had a couple worse, but the memory is too painful...