So, here we were in this musical disaster (the joyfullest NOISE you ever heard) about a minute in when (and I know you worship leaders out there already know what happened) I discovered that in all the frantic scrambling, I forgot to take the capo off.
I was playing in B. Everybody else was playing A.
So, the singers were all singing in B, while the rest of the band was frantically trying to make out what I was doing.