How do you view backing vocals played from tape (well a sampler) during live shows? They do thicken the lead vocal nicely and make things a bit more interesting.
Use sparingly. I'm all for backing tracks and support tracks, but vocals are the one thing where it looks/feels "fake" if its over-done. I personally prefer it when bands stick just using the verb/delay wet tracks as support on parts the have FX as "part of the song" full-on harmonized vocals through a whole set off the tape are going to make it seem like NOBODY on stage is playing. IMO, of course.
I agree having backing vocals throughout the whole song might be an overkill, but what if it's just harmonies and other bits in choruses? Kind of like using whammy harmony in guitar solos.
That's what Hamerfall does actually. It was weird when they got to choruses and there were 6 vocal lines behind the singer with noone else on the mic. If your drummer can lock to a click track and manage to keep it together I guess it might be worth a try. Michael Kiske managed to even lip sync to recorded vocals for the first half of the Helloween reunion tour with noone getting any wiser.
I wouldn't do it if i were you, especially if you're in a smaller band playing clubs with a sound guy that doesn't know how to handle it.
I think it's kind of the opposite If the sound engineer/PA isn't great, pre-mixed backingtracks are a way to even the odds and sound decent anyway. My band has 4 vocalists live, and on small stages they often don't cut through, sometimes the engineer mutes them entirely to fight mic bleed or feedback, and sometimes the venue can't even produce 4 mic stands in the first place (even when it's in our stage plot, that they obviously didn't read). So yeah, we're starting to experiment with backing tracked vocals as a failsafe. We spent all that time writing them and rehearsing them for a reason so it sucks to face a new audience and not have them. This way we have 3 harmony vocals at least, and 6 at best Why not.