Not exactly library music, but I've found commercial music from "Extreme Production Music" to be very interesting. I love their Dark Country series. I guess the story is they hired Blues Saraceno to make commercial music, and his rock-inspired country tunes took off, they started releasing albums of it. Outlaw blues, Garage Blues series, Swamp Rock,etc, albums created for commercial sales, but they found record sales profitable, glad too.
Spotify has a Label: search, you can search entire label catalogs, and that lead me to get some really nice albums that are made for genres.
Spotify has a Label: search, you can search entire label catalogs, and that lead me to get some really nice albums that are made for genres.