shortness of breath and off-key moments are expected at rock concerts because they don't use dance as part of their acts....half of pop music is the choreography, so it would be pointless to go to a pop concert if all they did was sit there and sing...hell even R&B acts do tons of choreography and lip-synching during live performances...the only times they actually sing is during slow songs...I'm not gonna fault them for it because dancing alone gets a person winded enough...if I'mnot mistaken, to NSyncs' credit, the alst time they performed at a VMA show, I believe it was to their song Pop, you could tell they were actually singing as both JC and Justin had some pretty bad off-key moments...but to expect them to do it all night long is ludacris...