Let’s cross over those unyielding mountains

It's been a while since I went all random on you, so you're stuck with a gem from the 1980s. Do you remember them? The shoulder pads? The hair? The dresses? They were a joy to behold.

Today's corker of a song comes from the 1984 edition, held in Luxembourg. And as they don't participate these days, I've gone for a country that is also having a few years out - Turkey. Will we ever see them back? I suspect not as they have their little Türkvizyon thingummy keeping them busy right now. But this was noteworthy in that our friends in Turkey liked to keep picking vocal groups, but never with a name like this particular group's. They're called Beş yıl önce on yıl sonra/Ten years after five years before. If you're a maths boffin, what year would that make it?