10 or so years ago, I went to see a big ticket band* for a not insignificant amount of money either, and it was clear that a significant part of the performance was being mimed - the drum sound, for example, didn't match what part of the kit was being hit... It really spoilt it for me, and I was really disappointed by the whole experience.
I've nothing against backing tapes or running sequences (I've used them, and my favourite live bands use them), but don't try to trick me, OK? ?
* The female lead singer of said band may or may not have very Blonde hair if you see what I mean.