I'm going to have to go ahead and plug SAGE[0], because between Spotify recommending me the same bands/songs ad nauseum (or just being way off), friends already telling me they used it to find a new band to listen to on the first day it launched, and just being a fan of his work in general, it's a complete labor of love and I think it shows.

[0] https://medium.com/@hate5six/sage-an-artificially-intelligen...