I feel sorry for Milli Vanilli. They were penniless and looking for singing work, very young and it wasn't, if you Google.,really explained to them that a lot of the stuff had already been recorded by session musicians and they were just eye candy. They wanted to sing but after a quick try out in the studio it was decided to go with the original recordings. Then they started having hits quickly, got nominated for a Grammy and had to go along with the juggernaut. They never wanted to con anybody, they wanted to sing. One went off the rails and died young.
I completely agree. They did actually want and expect to sing, but weren't allowed; but you'd have thought from all the criticism that they were scheming and in on it all along.
Not exactly the same thing (as it was them singing on the recording), but as I said earlier, miming on music shows was equally deceitful but routine for a long time. Also a bit different, but I (as a child, but not a young one) was very confused to find that the man singing amazingly and beautifully to a rather boring, simplistic backing track was actually called Seal, when I believed he'd been 'introduced' to us all as Adamski.
That still happens with the likes of David Guetta and Calvin Harris, where an often glamorous and brilliant singer is presented (i.e. staged) as the big star but (until they also get big) often not even named as one of the artists of the song.
I'm guessing that Frank Farian was probably a bit like this, albeit 'rather ahead of the curve'. From his perspective, he probably saw it that he was the talent who had written/commissioned a track, sorted all the arrangement, production and promotion, planned and co-ordinated all the styling, presentation, image etc. and all he needed to top it off was the relatively insignificant matter of somebody to provide the vocals.
He also worked on 'Rock 'n' Roll Mercenaries' with Meat Loaf and John Parr, and sang backing vocals, although, for some reason, he didn't look for stronger singers to replace Meat and John 