Turfster

spotify lets you download songs/albums and play them when in offline mode

It does. If you have spotify premium you can save as much music locally as your device will hold, either by selecting individual songs/albums or by playlist (which will update the local copy with any new tracks you add whenever you connect to internet again). I don't know if it's much of a thing anymore, but back in the 2010s there were programs to rip the local proprietary-format spotify files to mp3 so you could throw them on other devices as well.
EDIT: Looks like that is indeed still a thing

FWIW I'm not defending spotify here, just clarifying how it works. I was a spotify user for 12 years because I'm something of a playlist-brained music listener and it used to be great for that. But the past 5-6 years have been a steady decline in user experience not to mention the company's shitty behavior toward artists and musicians. I finally got around to dumping it this spring and haven't missed it all that much (really the only thing I do miss is being able to listen to all my podcasts in the same player as my music, and queue episodes and music concurrently). I shoved my playlists over to Tidal while I work on a longer-term solution to transition myself more completely away from streaming services.

type the artist and track title into soulseek

I quite like SomaFM's radio channels, it's been going since 2000

Another trick is looking up smaller cities in Bandcamp's location search, often turns up something interesting!

E: It seems to be on hiatus ATM, but @community-jukebox also has suggestions from Cohost users in different genres

discogs album recommendations from ones i like, and friends with similar tastes

vlc is always the correct media player to use

oh damn, thanks for sharing! it never occurred to me that VLC might be on mobile

I was about to mention this. VLC is a bit clunky but works, I used to use it on my older phone without a problem.

I will second power Amp, I have used it for years