As this thread is about history/evolution, it's worth pointing out that Abba called it a day this year, though they never explicitly said so. I'm not sure too many of us would have predicted, at that time, their subsequent revival. They petered out with a compilation but it had a new track that connects back to Bimbo's original list.
@BimboBob do you have any interesting insight on how Blancmange came to cover The Day Before You Came?
A mini soap opera with, as Rob would say, a casio keyboard style accompaniment, it was quite a strange but beguiling single for them to bow out on. I say beguiling possibly more because of the video, up to this point I think I'd only been interested in girls my own age; but it's entirely possible that the more mature iteration of the blonde one in this video was instrumental in a fascination with older women that took about a decade to shrug off and nearly cost me my job at one point.
I'm not nominating it but if there's a coda for this year it would be nice for it to be included!
Meanwhile the other one from Abba was busy enabling the habit of Britain's favourite drum effect addict. The Collins family should probably have staged an intervention and taken out an injunction against her. Not one for the coda!
Another near miss for my short list was the Go Gos with the original version of Our Lips Are Sealed which l only became familiar with after the subsequent Fun Boy Three version. The original just makes more sense given the underlying story of it's creation.