It must be weird playing in a band. I play solo, and have pretty well structured arrangements which I try to stick to in performance; although they tend to mutate over the weeks/months/years I play them. However, as McGrath plus others noted, sometimes the words disappear. But I know when this is happening and know when I'm going to vamp, or play the fill again til the words (hopefully) return. But with a band, how do you know. I guess the telepathy of having played together for yonks and LISTENING to each other's the answer, but I feel better knowing that everything's down to me. Also it makes rehearsals easier to organise.

But, to answer the question: I do all of the previous answers, plus sometimes put in a different tune or snippet, (such as most extremely, a bit of a Grover Washington version of Mr Magic played on harmonica between verses of The Wife of Usher's Well. It works. Trust me...)