One thing I like is when a band actually admits a mistake... Usually a massive mistake since no one notices the little ones. One old friend, a musician since the '70's, has stopped after the intro and said "That was not good. You deserve this to be better. Let's try that again." Everyone loves it, and it happens very rarely.
In my mind I can imagine a band member stopping everyone, telling the crowd "we(the band) have made a massive mistake and we'll try again and do better this time" while looking at the band with a fierce expression. Then he'll put his hand up to shield his face from the band and tell the crowd "actually it was me that messed up" as if the band can't hear him. Always best to address problems with a little humor.
In my mind I can imagine a band member stopping everyone, telling the crowd "we(the band) have made a massive mistake and we'll try again and do better this time" while looking at the band with a fierce expression. Then he'll put his hand up to shield his face from the band and tell the crowd "actually it was me that messed up" as if the band can't hear him. Always best to address problems with a little humor.