Marc,
As I said, I heard about those bands 20-25 years ago, word of mouth from friends. There barely was an Internet to obtain information, imagine streaming... So I did what any curious person would, I bought records blindly, from catalogs. And then started reading all I could find about these bands, and the countries/music scenes they were part of, mostly magazines and books, and some early Internet content. And, of course, tips from friends, like Tom who writes the blog I've posted.
After a while, you end up forming a base of knowledge, where you know what Roon knows, which is, that relationship between bands, who played where, which albums are good, etc. But that takes time and $$$. So, on one hand, everything's so much easier today, with all that information pre-digested and collected for you, it's also overwhelming in size and scope, so you have to be able to pick "starting points" and set into a journey, like I originally did.
Another early (musical) fixation of mine was the "kozmigroov" movement/scene of the late 60s/early 70s. That was the electrified jazz, progressive in nature, that blended all sorts of influences into a cool, hip, very 70s sound. Early on, a page served as a guide, and the curator of that page kept adding new "finds" within that genre.
http://www.freeform.org/music/kozmigroov.html
This very page is still around, grown in size tremendously. Back when I first looked at it, there were like 20-25 albums in there, so I, of course, proceeded to buy each and every one of them
Now, as you can see, would be quite a bit harder, given he's collected a lot more information, but still, if you set a starting point into that journey, that sort of information is priceless. I'm sure a good 70% of the albums on that page will be on Tidal, so you can save a lot of money (if you're anything like me, and want to have physical media of the albums you end up liking the most).