I personally HATE when people sing along. I try to enjoy kelly singing and the people behing are not singing, but yelling out-of-tune words that are not correct, and then they laugh when they realize they are wrong and start yelling again. Okay, I know that's specific, but it happens. I pay money to hear an artist, not someone who would be thrwon out of chorus clas. And even if they CAN sing well, save it for somewhere wgere people want to hear you.