My band played a show once where I saw the venue owners look of sheer horror when we started our first song. He cut the power. My bassist set his bass down and walked off the stage and I was right behind him. Somehow or another, the power got turned back on (we did pack the venue) and we played our full set. I hit the drums harder than normal, which is pretty hard to begin with. I am with the other people chiming in here, in that when I was booking shows for this band, I would tell people "we are a loud rock and roll band". We never really had a problem other than that one venue, which to be honest mostly hosted hippie-type acoustic music.