Actually, I have always hated it when backing singers aren't even allowed to be on stage (but hidden somewhere). I acutally think it deceives the audience since they cannot detect the sources of the other vocals.
There is definitely a big imbalance in the volume of the backing vocals in the chorus for Croatia and Azerbaijan compared with most other entries. I guess the effect is that having such a reliance on finely tuned and corrected vocals in some sections of the song, it makes the imperfections of the live sections stand out even more (Albina's "Oh nooooooooo" especially) so it may end up backfiring for those entries.
I think it depends on the production techniques involved in the original studio recording. You could tell that those two songs used major layering of the lead vocals that I guess stripping that away to just a single live vocal would sound empty to some degree, but I hope that delegations in the future would find the right balance of still raising the live vocal volume and keeping the back-up vocals in the background to avoid the one inevitable lip-syncing arguments.
Oh finally completely agree with you. I was happy when they said about prerecorded vocals (which means more people on stage dancing or whatever) but yeah... It'not good. I wish they can put 8-10 people limit. That 6 is meeh.There shouldn't be any future for allowing pre-recorded back-up vocals period! Fine if EBU truly is using the system this year to limit the amount of people, but it should be gone by next year and I think we can already see why.
Instead, rise the number of people who can be on stage (it's a change that is long overdue anyways), it's understandable that it hasn't been introduced this year but I'd be happy for a change like that even for next year. I think 8-10 people should be fine, no one will be forced to use that many people of course, but with entries that have dancers it can help balance with the live backing vocals needed to.
I only mentioned about the future since it's clear that the contest will continue to evolve and I wouldn't be surprised that the EBU pass a rule to allow pre-recorded backing vocals going forward despite the clear objections of many. Personally I don't see it as a major issue, but also I understand why others do have a major issue with it.
I think countries abusing it like Moldova will not do well so even if the rule stays it won't become a norm.Since we don't have the full performances to judge, perhaps once this edition is over, we will be able to tell how many delegations in total have taken advantage of the pre-recorded backing vocals and who are guilty of abusing them. That'll be something interesting to look into. And see how this has any impact on the results.