Does anyone remember 'the sixty one', I used to use that all the time to discover music, was really cool - sadly, I left with the rest after the redesign plus overall the music discoverability market was already shifting away from it: https://en.wikipedia.org/wiki/Thesixtyone
Not sure how well this works for what you have in mind, but it may help. I'm not a fan of the "just play stuff related to the artist I'm listening to" to find new things, rather I would prefer to get a list of artists and explore those on my own.