I will give it up for the 1950's -- "modern" jazz & Stockhausen & beat poetry & rockabilly & Scifi theremins -- but the 1940's not so much.
Bebop (c. 1946) was a necessary development but hasn't dated well. Swing and Bing and all that is even more moldy. But I confess I don't know much about the "rural" musics of that era (maybe it was a golden age for country -- when was Hank The First active again?)
The late 1920's into the 1930's was also a better era, with Fats and Duke and Armstrong and all those guys at the top of their game (alcohol prohibition was the golden age of jazz.) WW2 years bred a certain homogenization and conservatism -- The Andrews Sisters were the biggest thing then, you know?