Interesting thread. When I first started listening to music in my late teens thru my 20s, my sources of music discovery were the following:
1) My father who had an extensive collection of LPs in Jazz, Blues, Classic Rock and Hindustani classical.
2) Pecos in Bangalore which played music unlike anything I have heard before. I owe a lot of my discovery of prog rock, Canterbury, Latin Jazz, Punk Metal to my endless hours at Pecos after college and weekends. I am sure folks in Bangalore shall probably know the extensive collection of tapes at Pecos stacked behind the bar!
3) When I started buying music, it was Music World and a friendly staff there that let me 'borrow' CDs and try it out.
4) Finally, my college bandmates who listened to everything from Grateful Dead to Ali Toure Farka to Bhimsen Joshi to Chopin!
Now, I use Allmusic and Spotify recommendations almost exclusively besides a group of friends/music lovers who keep exchanging recommendations. Tidal playlists are quite good but their recommendation engine sucks!