Also, "I want 'random' songs that are musically appealing to hear in sequence." A sort of lite DJ logic, really; not necessarily modifying the songs' entrances and exits, but more selecting keys and tempos.
The only quirk I've noticed is when the same person has multiple bands... I've had it play Jack White or Les Claypool 4 times in a row, for example.
I'd much rather have these sub-genres woven together with changing styles at each track boundary, as a sort of counterpoint.
If I can remember all the way back to when I used to make my own "mix tapes" transferred from vinyl records, I think I used to do this sort of interleaving. So, I think my preference existed before I ever experienced the shuffle of a 5 or 10 disc Sony CD changers, which usually changed discs on every track change and avoided any repeats until the entire set was done.
Because of my preference for shuffle, I used to burn a CD or two for use in rental cars, where I added a pseudo-random prefix to the file names. This gave me a shuffled play when the in-dash player was set to just play sequentially, so I didn't have to discover a random mode with repeats in one particular car...
I'll probably spend a bit more time trying to get Spotify to work as I want, but in general it's resulted in me just listening to less music. I guess that's good for Spotify, since they're still getting paid (but not if it makes be question why I'm still paying them).
“What is the best to listen after this track?” - just with a super small subset of tracks.