I think things like this aren't done too often. & hence it was always a bit of a gamble, & they don't always come off.
I remember a half-time performance at my local football (soccer) team from a young & 'upcoming' Nottingham based girl band. (Spice girls wannabes). I think the accoustics were slightly better (although it was just a CD) that they were miming too. A few polite applause was what they got. Take into account however that the majority of ppl there r there for the sport & probably more worried @ halftime about their beer / pies / getting to the toilet / talking about the first half.
I also saw 'Bob the builder' at an away game. I think we were all throwing stuff at it!!
Mike