@Doug Kresse: I am willing to bet that asking the crowd how it sounds will not in 90% of shows make the sound any better. If the sound-person hasn't figured the bands' sound out on their own, they probably won't and just aren't that good at their job and/or are having technical problems. If they happen to be missing something crucial about the sound of the band, go tell them discreetly. It's insulting to call them out from the stage and won't yield the results you hoped for.