I listen to a lot of old music - 1950s, 1960s. I don't really have peers who listen to it so discoverability is a real issue. Pandora was amazing for me ~20 years ago, it introduced me to songs I never would have heard. Especially in the 50s you had a lot of "one hit wonders" so just listening to a band wasn't a great way to find other songs that I would like.

I don't really use Spotify so I can't compare but Pandora was awesome. I've found Youtube playlists to be the best replacement so far.