A lot of performers run auto-tune real time when they play live. I got to sit behind the board when a friend of mine ran sound for nsync. He let me hear the signal before it went thru the autotune box. hi-larious.
No. Apparently it kills your career (and it took him a long time to get enough connections to get that gig.) Similarly, I heard the guy who ran Ashlee Simpson's sound on SNL was kind of booted out of the business.
The thing is, when you pay $50+ for a ticket you're paying for talented artist... I suppose the engineer should be considered the artist not the 'singer'.
I saw a band called "Metrostation" a few months ago. The place was sold out with tweens who were having the time of their life loving this amazing band.
Funny thing was, the band was not playing. Everything was tracked on 2 macs run by a chubby guy in a phillies hat on the side of the stage.
I'd argue the majority of people who go to these shows have no clue and will gladly pay their $50 just to see famous people and tell their friends.