Hmmm... Did they, really? I live about 1.5Km from the War Museum (that's where BluesFest is held) and I didn't hear anything. Unlike last year where even with the windows closed I could hear the lyrics(!) and as far as I know, the # of decibels was much lower. I can understand how people living just a few hundred metres away would freak out though - I've walked by a few times and that was pretty loud (doesn't help that they had a stage facing my residential area! That's why I called the cops.)
According to wikipedia, so consider the source. And I corrected your post
