When i just plain don't know the song. I am not one of the regular musicians, i just fill in on Fridays and some Sundays.
As if thats not bad enough. I was once supposed to play for a birthday thanksgiving in church. I get there and i am the only musician there. OK, i start to panic; no drummer, no bassist, NOTHING. I don't know how to work the blessed MO8 and the other keyboardist has done something fancy so no sound comes out. Luckily i have brought my guitar so we can do SOMETHING. One of the men decides to back me up on drums, he is not a drummer but can beat around. I say ooooookay 
. We start playing and this dude is SO off-beat its ridiculous.
THE P&W leader does the hand wave thing to me. I'm sure someone has got it at one point, the one that says "Thank ya' brutha, you can stop playing now. We see the zeal of the Lord in you but ah thinks we can handle it ourselves. Thank ya' though, God bless ya."
This was in front of everyone and i was SO embarrassed cuz people KNOW what the hand wave thing means. 
Oh, the dreaded hand-wave. In my church, it's a fist in the air, angled in the musician's direction. When I first started playing the keyboard, I became pretty familiar with that fist....still have nightmares about it....lol
