That's something I'd actually pay good money for - a streaming music service with a library as extensive as the major contenders (or better yet let me bring my own!), which learns my preferences not in isolation, but tracking how they affect each other and environment - this song is normally followed by that song, or this song usually gets skipped if playing while driving etc.
None of the music services seem to understand that just because you like multiple genres, that doesn't mean that you want it to randomly jump around between them without any consideration for how they flow together.