Regarding discovery specifically, this sounds ridiculous but genuinely Youtube is pretty decent for it. You just need to punch in some more obscure stuff you already like (preferably in a clean session) and it often does pull up relatively interesting recommendations.
music
Post well known tunes into the megathread. Post fresh vibes individually.
π΅ Hexbear music streaming den πΆ
PipePipe for ad-free YouTube on mobile + ultradiskopanorama channel for the jams
Soulseek is a p2p client originally a contemporary of the likes of Napster and Kazaa but it has survived and kept an active user base into the modern day. Somewhere about a decade ago whenever what.cd went down a bunch of the content got dumped onto Soulseek where it has lived ever since
I host a large library of files and whenever someone downloads something from me I go and browse their collection and look for at least one album to download and add to my collection. I have found some interesting audio this way
last.fm and rateyourmusic are both good for finding new music. rym notifies you of new and upcoming releases by artists you select. neither of the services have great algorithmic recommendation, but it's very easy to fall down discovery rabbitholes. rym in particular has tons of recommendation lists made by users, and a very fine-tuneable search/filter system.
I've been sort of a bleeding-edge (ie very new) music enjoyer. Most artists release music to streaming services on Thursdays at midnight, because midnight is Friday and Friday is the start of the weekend when people get off work.
On Thursday night, I look at the link below to see a list of new albums which were released and then I search for them on youtube music. I just try out different new albums. You can also click the month button to see the most popular albums of each month.
https://www.albumoftheyear.org/upcoming/
RateYourMusic (RYM) is a popular website where you can rate and review music.
https://rateyourmusic.com/charts/
My dream service would be one that could recommend music based on a given song, and provide details about the artist and things. And even better version would have an API I could tap into so I could connect the service to music assistant. Hell I'll make a (mostly) locally hosted version of the spotify dj if I can.
You're pretty much describing 'last.fm'? It tracks the music you listen to in a similar way to spotify. You can install the plugin in your media player and then the website records the names of the files you play and recommends you similar music. Some people says that it's an invasion of privacy and there's an alternative site called 'librefm'.
Listenbrainz might do at least some of what you want, but I must confess I haven't made heavy enough use of it to actually vouch for it.
Personally whenever I get a craving for new music I load up either gnoosic or music-map and poke around. I think they both use the same database though, so it just depends which interface you like better.
For actually sourcing music, soulseek still exists (unsure if I'm allowed to link that here, but it's not hard to find) and has a mobile client on f-droid. It's also half decent for discovery too, since you can browse folders of people who show up in searches.
one more olde way if you listen to out there stuff, is to go by producers/small labels/studios names of bands you already like and quickly checking bandcamp of other projects by them. Doesnβt work with popular music, works fine-ish with indies/small bands (now studios tell you the least, but producers/labels sometimes have fairly obvious tone) *(fine-ish in that you find some gems with 5-50% chance, depending on strength of producer/label niche, which have like 1-30k views on youtube, so that you make those bands much happier than getting ai ambient thingies/or bigger labels)
This works great for jazz.
Itβs works great for rock and synth as well, obviously i miss some stuff which is self published or big, and only algos will get there, but getting a lot of small bands for algos gives you such rich choice, when (i think) with bigger bands you get like normalized average taste with random quirks thrown in
Youtube Music is probably the best for algorithmic recommendations and you can very easily block ads on it.
but if you want to try a different approach entirely, nothing beats just asking around for recommendations. If you find some people with similar taste as you to trade recommendations with, it is the most satisfying and fun way to discover new music.
poiskm.net is my favorite way to nab obscure songs mainly from the Former Soviet Union, not super relevant for you but I might as well give it a shoutout here because it is a good ad-free service for discovering new music
Edit: Linux Mint also comes prepackaged with Shortwave, fun little radio app
QOBUZ is pretty good as they have an actual magazine
Soundcloud I guess
Soundcloud has ads

It has??? I have never listened to any
Depends on what you're listening to I guess. Or you have ad block (I need this for my phone)

uBlock Origin is available for Firefox mobile and its various forks
I use the app in my phone and have never heard any ad.
Rateyourmusic and bandcamp