From Roon 1.8 is live!:
Genre Pages
Genre pages were previously limited to the music present in your library, but in Roon 1.8 you can explore music that’s new to you.
Genres that were previously unavailable or only featured a handful of content from your library now feature a number of recommendations powered by Valence, including recommended artists and albums, subgenres, Live Radio stations, and for classical music top composers and compositions.