I have had this argument before ....and while it gives you a certain degree of coolness to like retro music there is a fine line.........
Liking ABBA including the kitchness of their outfits abd Cause one of them had a nice bum is cool, liking Joe Dolce (of Shutuppayaface fame) your veering towards the looking like a dickhead swingometer.
Its like one matchstick out of the side of your mouth swings to cool, one matchstick either side Hello Dickhead
For me, pop music stopped being cool around the mid-70's, so I suppose it's relative. :-)
Significant? To who?
Words are funny things.
For example it is impossible to like the Spice Girls, ABBA or Rebecca Slack and claim to be cool