I've been talking to a lot of record producers/mixers/recorders and the general impression I'm getting is that there is a LOT of post-event stuff that gets recorded and tracked into live albums (ok, duh I knew that already).
One of them sarcastically said 'cos we'd never take a studio track and just put a congregation singing behind it haha'.
hmm, i understand (especially) if the singing wasn't that great on the night, but I don't like buying live albums now, just doesn't seem... right.