n80, One way to learn about blues recordings is by reading. Much has been written about the blues and which are the best examples of different subgenres such as delta blues, Piedmont blues, Chicago blues, Texas blues, etc.
The thing is, many blues lovers don't care about sound quality. Performance is considered much more important by many writers. But there is enough writing around, both on the net and in print, that you should be able to find the cds you want to add to your collection.
Here is just one place to start for country blues:
https://www.allmusic.com/subgenre/pre-war-country-blues-ma0000011871/albums
The thing is, many blues lovers don't care about sound quality. Performance is considered much more important by many writers. But there is enough writing around, both on the net and in print, that you should be able to find the cds you want to add to your collection.
Here is just one place to start for country blues:
https://www.allmusic.com/subgenre/pre-war-country-blues-ma0000011871/albums