Well, you're bringing up a difficult task here. You're right, if somebody samples Bruces voice and plays it on keys, that could be very interesting. I can imagine something like the layered Bruce parts in Book of Thel, but played live, maybe more in an experimental kind of band. It's a fine line, because sampling can be absolutely great - sometimes, if it makes sense, even if it ISN'T played live (e. g. something like this
www.youtube.com/watch?v=Kj6zNmzbO8E).
However, in the context of Powerslave, that's not the case IMO. Backing vocals in a live rock band as Maiden should be sung live or (if they can't do it) be left out. I think that backing tracks that are just there to beef things up but have no essential function, even in a more experimental band - Meshuggah do that unfortunately - are cheating. I mean, Maiden themselves say they don't like "playing" with playback - but where does that start?
I could go on and ramble for ages (I would certainly bring up the subject of click tracks that I hate with live bands) and I would never be able to proof my points, because ultimately it probably comes down to taste, also I've got to go, so I'll stop here. But I'm interested in the opinions of you guys.
@Forostar, what's your standpoint?
@jazz from hell
A few examples of simulating/playing (along) (with) vocals on stage.
Epica let their big choirs run from tape/minidisc. This masks the (own) abilities of Simone's lead vocals somewhat since she sings along during many of these parts but no one on stage acts as if they sing along. Usually there are no extra microphones for backing vocals. Only when there is a guest vocalist.
Blind Guardian also have their choirs played on stage but band members sing along. But their voices sound so soft (and the tape sounds loud) that I wonder why they sing a long. I can only hope that people do not have the impression that the band members do all the vocals because then it would border to cheating. Acting as if band members
really contribute to the vocal aspect of a show, I don't like that.
Dream Theater. I read a review that says that John Petrucci playbacked his own backing vocal during a concert of this tour. Some other forum members (some have seen other shows themselves) deny this, or even if it happened, they deny its importance. Still, I doubt if the man's voice can be heard for real, or that it
really contributed when the tape is way louder. And that's the point.
Now let's see how Maiden's Powerslave fits in this context. In 1984 and
1985 live shows the Powerslave backing vocals were left out. I never forget my first listening session of the album
Powerslave, which was a while
after having heard
Live After Death. It was a "wow, this is great"-moment during the chorus of the title track. Why they were left out, or why other band members did not do backing vocals, we can only guess. But.. they weren't done.
Fast forward to 1997, 1998 and 1999. Bruce Dickinson played Powerslave with his band. And the "choir" returned. Choir? Well, they turned up in the shape of two backing vocals. Eddie Casillas and Adrian Smith did the job. An awesome result if I may say so. Check
here. Apparently someone came up with the idea, someone had the wish to make the chorus a little more epic, a little more bombastic.
So, in the Spring of 1999, the "choir" was still present in Bruce's set. A few months earlier, Bruce and Adrian returned to Maiden. The Ed Hunter Tour happened. Powerslave returned or stayed in the set, depending from which point of view we're looking. ;-)
The backing vocals were
gone. Perhaps Steve didn't want to do it, or perhaps it didn't work after trying in rehearsals, anyway, the approach turned out the same as in the World Slavery Tour.
Then in 2008 and 2009 the song popped up once again. Someone must have suggested that the chorus could need a bit of extra bombast. What we
hear is some kind of choirish keyboard, played by Michael Kenney. You'll notice that after the last chorus, the keys continue and are played along until the end.
In 2016 we have something, some of us think is not played by Kenney, and some of us think he does play it. First I thought he plays it because the whole (all exact notes) did
not sound exactly the same as on the original album, but now I am not sure anymore. Judge yourself here:
1984, from
Powerslave album:
click
2016, from The Book of Souls World Tour:
click
In any case, it is something that's not portrayed as being sung by someone on stage. In my opinion, compared to the Blind Guardian and Dream Theater backing vocal "performances" the Powerslave samples (even if they are not played) are not a big deal. Still, I prefer real sung backing vocals.
I do agree with
@The Mid-Distance Runner that I rather see Maiden playing all their own parts as in Aces High and Caught Somewhere in Time, but at least, the band does not act as if they are playing these parts. I indeed think that Bruce liked the extra echo effect of his intro thing in If Eternity Should Fail but I also think that the original vocals served as a cue. It helped Bruce with starting his lines. He could have used in ear audio, but -as noted by Brigs- he probably liked the extra echo effect to be heard for the audience.